ANTI-BOLUS CONTROL METHOD AND CORRESPONDING DEVICE

• US 20120215170A1
• Filed: 09/29/2010
• Published: 08/23/2012
• Est. Priority Date: 10/02/2009
• Status: Active Grant

• Current Assignee: Fresenius Vial SAS (Else Kröner-Fresenius-Stiftung)
• Original Assignee: Fresenius Vial SAS (Else Kröner-Fresenius-Stiftung)
• Inventors: Traversaz, Philippe, Archat, Damien
• Granted Patent: US 9,770,550 B2
• Time in Patent Office: Days
• US Class Current: 604/155
• CPC Class Codes: A61M 5/14546 Front-loading type injectors
• CPC Class Codes: A61M 5/1456 with a replaceable reservoir comprising a piston rod to be moved into the reservoir, e.g. the piston rod is part of the removable reservoir

Abstract

For controlling the movement of the push device of a pump of the syringe driver-type, the pump comprising a casing (100), a syringe cradle (200) for a syringe (400), a push device (300) mobile relative to the casing (100) and capable of being driven in rotation parallel to the longitudinal axis of the syringe by driving means, clutch means (310, 350, 351) for engaging or disengaging the push device on the driving means, the push device is disengaged from the driving means, in order to move it manually, and the presence or absence of a contact between the push device and the syringe head is determined. If the push device is not in contact with the syringe head, it is advanced manually. Blocking of the advance movement of the push device is triggered only if, at the beginning, the push device was not in contact with the syringe head.

Claims

1. Method of controlling the movement of the push device of a pump of the syringe driver-type, the pump comprising a casing, a syringe cradle in which a syringe is placed, a push device mobile relative to the casing and capable of being driven in translation parallel to the longitudinal axis of the syringe by driving means, and clutch means for engaging or disengaging the push device on the driving means, said method comprising the following steps:

a) disengaging the push device from the driving means;

b) detecting the presence or absence of contact between the push device and the syringe head;

c) moving the push device in translation toward the syringe if there is no contact between the push device and the syringe head, detecting the contact of the push device with the syringe head and immediately actuating means for blocking the translation movement of the push device which had been inactivated up to then.

2. Method according to claim 1, comprising the following additional steps performed after step c):

d) engaging the push device on the driving means;

e) unblocking the translation movement of the push device.

3. Method according to claim 2, comprising the following additional steps performed after step e):

f) disengaging the push device from the driving means;

g) moving in translation, by the desired amplitude, the push device in contact with the syringe head in direction of the syringe;

h) stopping the movement of the push device and engaging the push device on the driving means.

4. Method according to claim 1, comprising the following additional steps performed after step b) in the case of detecting the presence of a contact between the push device and the syringe head at said step b):

g′

) moving in translation, by the desired amplitude, the push device in contact with the syringe head in direction of the syringe;

h′

) stopping the movement of the push device and engaging the push device on the driving means.

5. Method according to claim 2, comprising the following additional step performed after step e) or h), respectively:

i) actuating the driving means of the push device.

6. Method according to claim 2, said method being applied to a pump whose push device is driven by a threaded driving rod by means of two half-nuts capable of being moved between an engaged position in which the two half-nuts are brought close to each other and surrounding the threaded driving rod so that they can move on it only when it is set in rotation, and a disengaged position in which the two half-nuts are brought away from each other and from the threaded driving rod so that they no longer cooperate with it, said method comprising the following intermediate steps performed after the engagement of steps d) or h), respectively:

d′

/h″

) detecting the relative position of the half-nuts;

d″

/h″

) if the two half-nuts have not reached the engaged position, setting the threaded driving rod in rotation, until the two half-nuts have reached the engaged position.

14. Method according to claim 6, wherein, in step d″

/h″

), if the two half-nuts have not reached the engaged position, the threaded driving rod is set in rotation by controlling the effort generated by the push device on the syringe via a force sensor integrated with the push device.

15. Method according to claim 3, comprising the following additional step performed after step e) or h), respectively:

i) actuating the driving means of the push device.

16. Method according to claim 4, comprising the following additional step performed after step e) or h), respectively:

i) actuating the driving means of the push device.

17. Method according to claim 3, said method being applied to a pump whose push device is driven by a threaded driving rod by means of two half-nuts capable of being moved between an engaged position in which the two half-nuts are brought close to each other and surrounding the threaded driving rod so that they can move on it only when it is set in rotation, and a disengaged position in which the two half-nuts are brought away from each other and from the threaded driving rod so that they no longer cooperate with it, said method comprising the following intermediate steps performed after the engagement of steps d) or h), respectively:

d′

/h″

) detecting the relative position of the half-nuts;

d″

/h″

) if the two half-nuts have not reached the engaged position, setting the threaded driving rod in rotation, until the two half-nuts have reached the engaged position.

18. Method according to claim 4, said method being applied to a pump whose push device is driven by a threaded driving rod by means of two half-nuts capable of being moved between an engaged position in which the two half-nuts are brought close to each other and surrounding the threaded driving rod so that they can move on it only when it is set in rotation, and a disengaged position in which the two half-nuts are brought away from each other and from the threaded driving rod so that they no longer cooperate with it, said method comprising the following intermediate steps performed after the engagement of steps d) or h), respectively:

d′

/h″

) detecting the relative position of the half-nuts;

d″

/h″

) if the two half-nuts have not reached the engaged position, setting the threaded driving rod in rotation, until the two half-nuts have reached the engaged position.

7. Pump of the syringe driver-type comprising a casing a syringe cradle intended to receive a syringe, a push device mobile relative to the casing and capable of being driven in translation parallel to the longitudinal axis of the syringe by driving means, clutch means for engaging or disengaging the push device on the driving means, the pump being equipped with means for blocking the movement of the push device toward the syringe when the push device contacts the syringe head during a movement from a position without contact with the syringe head toward a position in contact with the syringe head, wherein the means for blocking the push device comprise a threaded control rod, a nut engaged on the threaded control rod and integral with the push device, a brake acting on the threaded control rod.

8. Pump according to claim 7, wherein the brake is constituted by an electromagnetic brake comprising a rotor integral with the threaded control rod and a stator integral with the casing.

9. Pump according to claim 7, wherein the push device is equipped with a contact sensor to detect the presence or absence of contact between the push device and the syringe head.

10. Pump according to claim 7, wherein the driving means are constituted by a motor and a threaded driving rod driven in rotation by the motor.

11. Pump according to claim 10, wherein the clutch means are constituted by a clutch lever located outside the casing, a push rod integral with the lever and two half-nuts capable of being moved from an engaged position in which they surround the threaded driving rod so as to be capable of cooperating with it and a disengaged position in which they are moved away from the threaded driving rod so that they do not cooperate with it.

12. Pump according to claim 7, wherein at least one engagement sensor is provided to determine if the push device is engaged or disengaged on the clutch means.

13. Pump according to claim 12, wherein the engagement sensor or sensors are placed on the push device and/or on the clutch means.

19. Pump according to claim 8, wherein the push device is equipped with a contact sensor to detect the presence or absence of contact between the push device and the syringe head.

20. Pump according to claim 8, wherein the driving means are constituted by a motor and a threaded driving rod driven in rotation by the motor.