Medication infusion system and method

Abstract

A medication infusion system may include a controller and a reservoir module including a reservoir containing medication to be delivered to an internal wound site via the controller. The controller may have a peristaltic pump driven by a motor to urge medication to flow toward the internal wound site. The controller and the reservoir module may each have a mating surface oriented such that the reservoir module can slide into engagement with the controller along a direction parallel to an axis of rotation of the motor. The mating surfaces may have features such as dovetails that facilitate secure assembly and retention. A reservoir module may include only a single reservoir for infusion, or two separate reservoirs for infusion and aspiration. One single controller may be capable of mating with either type of reservoir module to provide only infusion, or infusion combined with aspiration, as desired.

1 . A method for coupling a first reservoir to a controller of a system for percutaneous infusion of an internal wound site, the controller having a motor operable to urge a first fluid from the first reservoir toward the internal wound site, the motor having an axis of rotation, the method comprising:
 aligning a mating surface coupled to the first reservoir with a mating surface of the controller; and   moving the first reservoir along an attachment plane substantially parallel to at least one of the axis of rotation and an output shaft coupled to the motor to drive a pump to mate the mating surfaces together, thereby positioning the first reservoir alongside the motor.   
   
   
       2 . The method of  claim 1 , wherein each of the mating surfaces has a generally planar shape, wherein each of the mating surfaces has a dovetail feature, wherein moving the first reservoir along the attachment plane comprises causing the dovetail features to mate with each other to restrict withdrawal of the mating surfaces from each other along a direction generally perpendicular to the axis of rotation. 
   
   
       3 . The method of  claim 2 , wherein the dovetail feature of one of the mating surfaces comprises a central plateau having two flared edges, wherein the dovetail feature of the other of the mating surfaces comprises a central recess shaped to receive the central plateau in interlocking fashion, wherein causing the dovetail features to mate with each other comprises sliding the central plateau into the central recess. 
   
   
       4 . The method of  claim 3 , wherein each of the central plateau and the central recess tapers along the attachment plane, wherein sliding the central plateau into the central recess comprises decreasing a clearance between the central plateau and the central recess as the first reservoir moves toward a fully interlocked position with respect to the controller. 
   
   
       5 . The method of  claim 4 , wherein one of the mating surfaces comprises a locking recess and the other of the mating surfaces comprises a nub, wherein moving the first reservoir toward the fully interlocked position comprises sliding the nub into engagement with the locking recess to keep the first reservoir in the fully interlocked position with respect to the controller until a threshold level of force is applied to remove the nub from engagement with the locking recess. 
   
   
       6 . The method of  claim 1 , wherein the controller further comprises a peristaltic pump driven by the motor, the peristaltic pump comprising a plurality of rotors that rotate about the axis to urge the first fluid to move through a tube leading toward the internal wound site, wherein moving the first reservoir along the attachment plane comprises moving the tube into engagement with the rotors. 
   
   
       7 . The method of  claim 6 , further comprising stretching the tube around the rotors such that tension in the tube causes opposing sides of the tube to press against each other proximate each of the rotors to impede flow of the first fluid past the rotors. 
   
   
       8 . The method of  claim 6 , wherein the controller further comprises a blockage sensor that measures preferential distention of the tube along a direction perpendicular to the tube to determine whether the tube is blocked, wherein moving the first reservoir along the attachment plane further comprises moving the tube into engagement with the blockage sensor. 
   
   
       9 . The method of  claim 1 , wherein moving the first reservoir along the attachment plane further comprises moving a second reservoir along the attachment plane, wherein the second reservoir is shaped to contain a second fluid, wherein the controller is further configured to aspirate the internal wound site by urging the second fluid into the second reservoir from the internal wound site. 
   
   
       10 . A method for percutaneously infusing an internal wound site, the method comprising:
 determining whether aspiration of the internal wound site is to be carried out;   selecting one of a first reservoir module and a second reservoir module based on whether aspiration of the internal wound site is to be carried out, the first reservoir module comprising a first reservoir connectable to infuse the internal wound site with a first fluid, and a second reservoir connectable to aspirate a second fluid from the internal wound site, and a second reservoir module comprising a first reservoir connectable to infuse the internal wound site with the first fluid, exclusively of any second reservoir connectable to aspirate the second fluid from the internal wound site; and   mating the selected reservoir module to a controller such that the controller is able to urge the first fluid to flow toward the internal wound site.   
   
   
       11 . The method of  claim 10 , wherein the controller comprises a mating surface, wherein the second reservoir module further comprises a second reservoir retainer shaped to retain the first and second reservoirs of the second reservoir module, wherein each of the first and second reservoir modules comprises a mating surface, wherein mating the selected reservoir module to the controller comprises mating the mating surface of the controller to the mating surface of the reservoir retainer of the selected reservoir module. 
   
   
       12 . The method of  claim 11 , wherein the controller comprises a pump driven by a motor to urge the first fluid to flow toward the internal wound site, the motor having an axis of rotation, wherein the mating surface of the controller extends generally parallel to the axis of rotation, alongside the motor, wherein mating the selected reservoir module to the controller comprises receiving the mating surface of either of the first and second reservoir retainers in response to motion of the mating surface of either of the first and second reservoir retainers along an attachment plane substantially parallel to at least one of the axis of rotation and an output shaft coupled to the motor to drive the pump. 
   
   
       13 . The method of  claim 12 , wherein the mating surface of the controller has a dovetail feature, wherein mating the selected reservoir module to the controller comprises mating the dovetail feature of the controller with a dovetail feature of the mating surfaces of the selected reservoir module in response to sliding of the mating surfaces against each other to restrict withdrawal of the mating surfaces from each other along a direction generally perpendicular to the axis of rotation. 
   
   
       14 . The method of  claim 10 , wherein the controller comprises a peristaltic pump comprising a plurality of rotors, the method further comprising rotating the rotors to urge the first fluid to move through a tube leading toward the internal wound site. 
   
   
       15 . The method of  claim 14 , wherein the controller comprises a second pump, the method further comprising operating the second pump to urge the second fluid to move into the second reservoir. 
   
   
       16 . The method of  claim 10 , further comprising sliding the first reservoir of the first reservoir module into a cavity of the first reservoir retainer such that the first reservoir substantially fills the cavity, wherein, aside from the cavity, the first reservoir retainer is sufficiently solid to be incapable of receiving any other reservoir connectable to provide fluid communication with the internal wound site. 
   
   
       17 . The method of  claim 10 , wherein the second reservoir module further comprises a second reservoir retainer having a first cavity and a second cavity, the method further comprising:
 sliding the first reservoir of the second reservoir module into the first cavity; and   sliding the second reservoir of the second reservoir module into the second cavity.