Medical injector systems

• US 20040158205A1
• Filed: 03/10/2003
• Published: 08/12/2004
• Est. Priority Date: 07/10/2000
• Status: Active Grant

• Current Assignee: Bayer Healthcare LLC (Bayer AG)
• Original Assignee: Medrad Incorporated (Bayer AG)
• Inventors: Savage, Rodney Brian
• Granted Patent: US 7,682,345 B2
• Time in Patent Office: Days
• US Class Current: 604/151
• CPC Class Codes: A61M 2005/14553 comprising a pressure jacket
• CPC Class Codes: A61M 2205/11 with means for preventing cross-contamination when used for multiple patients
• CPC Class Codes: A61M 2205/14 Detection of the presence or absence of a tube, a connector or a container in an apparatus
• CPC Class Codes: A61M 2205/215 Tilt detection, e.g. for warning or shut-off
• CPC Class Codes: A61M 2205/587 Lighting arrangements
• CPC Class Codes: A61M 2205/60 with identification means
• CPC Class Codes: A61M 5/007 for contrast media
• CPC Class Codes: A61M 5/14546 Front-loading type injectors
• CPC Class Codes: A61M 5/14566 with a replaceable reservoir for receiving a piston rod of the pump
• CPC Class Codes: A61M 5/1458 Means for capture of the plunger flange
• CPC Class Codes: A61M 5/31513 Piston constructions to improve sealing or sliding
• CPC Class Codes: A61M 5/31515 Connection of piston with piston rod
• CPC Class Codes: A61M 5/347 rotatable, e.g. bayonet or screw A61M5/344 takes precedence
• CPC Class Codes: A61M 5/348 snap lock, i.e. upon axial displacement of needle assembly A61M5/344 takes precedence
• CPC Class Codes: A61M 5/36 with means for eliminating or preventing injection or infusion of air into body dialysis systems, blood oxygenators A61M1/14; haemofiltration equipment A61M1/34; automatic tube cut-off A61M39/281
• CPC Class Codes: A61M 5/5066 Means for preventing re-use by disconnection of piston and piston-rod

Abstract

A medical injector system for injecting fluid from a syringe (300) into a patient, the syringe (300) having a barrel (300) and a plunger (310), the plunger (310) comprising an inner surface having an engaging portion (311) adapted to be releasably engaged by a plunger handle (130) which has a retention member (142) adapted to releasably engage the engaging portion (311) of the plunger (310); and a syringe holder comprising a cradle member (200) adapted to receive a barrel (300) of the syringe (300) and a pivotable catch (500) to releasably lock the syringe (300) in the cradle member (200).

Claims

1. A syringe holder for a medical injector system comprising:

(i) a cradle member adapted to receive a barrel of the syringe; and

(ii) a pivotable catch to releasably lock the syringe in the cradle member wherein the catch is biased towards a first position and engages the syringe at the first position and disengages the syringe at a second position.

2. A syringe holder according to claim 1 comprising a positioning device located on the cradle member to locate one end of the syringe in a predetermined location in the cradle member.

3. A syringe holder according to claim 1 wherein the cradle member is a sleeve.

4. A syringe holder according to claim 3 wherein the sleeve is adapted to support the syringe against expansion under pressure.

5. A syringe holder according to claim 1 wherein the catch engages a front shoulder of the syringe.

6. A syringe holder according to claim 1 wherein the catch engages the syringe through a hole defined in the cradle member.

7. A syringe holder according to claim 1 wherein the cradle member has a biasing member to partially eject the syringe from the cradle member upon release of the catch.

8. A syringe holder according to claim 7 wherein the biasing member comprises a spring.

9. A syringe holder according to claim 7 wherein the biasing member is adapted to engage and minimise rotation of the syringe.

10. A syringe holder according to claim 1 wherein the front shoulder of the syringe is of a complimentary shape to an engaging portion of the catch.

11. A syringe holder according to claim 10 wherein the engaging portion of the catch is concave.

12. A syringe holder according to claim 10 wherein the engaging portion of the catch is convex.

13. A syringe holder according to claim 10 wherein the catch is wedge shaped.

14. A syringe holder according to claim 1 wherein it comprises an engagement portion to enable simple releasable engagement with a medical injector.

15. A syringe holder according to claim 14 wherein the engagement portion comprises a locking member.

16. A syringe holder according to claim 15 wherein the locking member comprises a slot.

17. A syringe holder according to claim 15 wherein the locking member comprises a pin.

18. A syringe holder according to claim 15 comprising a blocking member to regulate disengagement of the holder from the medical injector.

19. A syringe holder according to claim 18 wherein the blocking member stops disengagement of the holder from the medical injector if a syringe is present in the holder.

20. A syringe holder according to claim 18 wherein the blocking member stops disengagement of the holder from the medical injector if the plunger is not in a particular position.

21. A syringe holder according to claim 19 wherein the blocking member stops disengagement of the holder from the medical injector if the plunger is not in a sufficiently retracted state.

22. A syringe holder according to claim 1 for use with a medical injector system according to claim 183.

23. A syringe holder according to claim 1 for use with a medical injector system according to claim 189.

24. A syringe holder according to claim 1 for use with a medical injector system according to claim 193.

25. A syringe holder according to claim 1 for use with a medical injector system according to claim 201.

26. A syringe holder according to claim 1 for use with a medical injector system according to claim 205.

27. A syringe holder according to claim 1 for use with a medical injector system according to claim 213.

28. A syringe holder according to claim 1 for use with a syringe according to claim 154.

29. A syringe holder according to claim 1 for use with a syringe according to claim 155.

30. A method of filling a syringe with medical fluid from a sealed vessel the syringe for use with a medical injector system comprising a syringe holder according to claim 1, comprising the steps of:

(i) elevating the front portion of the syringe relative to the back portion;

(ii) advancing a plunger to a position within the syringe corresponding to a predetermined patient dose;

(iii) controlling movement of the plunger in a sequence of forward and backward movements to expel air from the syringe and any attached tube into the vessel bottle, and draw the desired dose of fluid into the syringe.

31. A method of filling a syringe according to claim 30 further comprising the step of automatically restricting the direction of movement of the plunger depending on the orientation of the syringe.

32. A method of filling a syringe according claim 31 wherein the plunger may move either forward or backward when oriented with its front portion elevated with respect to its back portion and only in the forward direction when oriented with the back portion elevated with respect to its front portion.

33. A method of injecting a patient using a medical injector system comprising a syringe holder according to claim 1 comprising the steps of;

(i) engaging a plunger with a hub slidingly engaging the barrel of a syringe

(ii) driving the hub along the syringe barrel; and

(iii) expelling fluid from the syringe into a patient.

34. A method for engaging a syringe holder according to claim 14 with a medical injector, comprising the steps of;

(i) aligning the engaging portion of the syringe holder with a complimentary portion on the medical injector, and

(ii) engaging the syringe holder with the medical injector.

35. A method for disengaging a syringe holder according to claim 14 from a medical injector, comprising the steps of;

(i) disengaging the engaging portion of the syringe holder from the medical injector; and

(ii) removing the syringe holder from the medical injector.

36. A method for loading a syringe into a syringe holder according to claim 1, comprising the steps of;

(i) inserting a syringe barrel in the cradle member such that the catch is displaced; and

(ii) allowing the catch mechanism to return into its biased position to engage the syringe and thereby retain the syringe in the cradle member.

37. A method for removing a syringe, from a syringe holder according to claim 1 comprising the steps of;

(i) releasing the catch to unlock the syringe; and

(ii) withdrawing the syringe from the cradle member.

38. A syringe holder according to claim 1 for use with a syringe comprising a hub according to claim 43.

39. A syringe holder according to claim 1 for use with a plunger according to claim 74.

40. A syringe holder according to claim 1 for use with a plunger according to claim 109.

41. A syringe holder according to claim 1 for use with a sensing system according to claim 157.

42. A syringe holder according to claim 1 for use with a sensing system according to claim 166.

68. A hub according to claim 43 for use with a syringe holder according to claim 1.

104. A plunger according to claim 74 for use with a syringe holder according to claim 1.

131. A plunger according to claim 109 for use with a syringe holder according to claim 1.

163. A method for engaging a syringe holder according to claim 14 with a medical injector comprising the steps of;

(i) aligning the engaging portion of the syringe holder with a complimentary portion on the medical injector; and

(ii) engaging the syringe holder with the medical injector.

(iii) detecting a level of engagement between the syringe holder and the medical injector system.

164. A method for disengaging a syringe holder according to claim 14 from a medical injector comprising the steps of;

(i) disengaging the engaging portion of the syringe holder from the medical injector; and

(ii) removing the syringe holder from the medical injector

(iii) detecting a level of disengagement between the syringe holder and the medical injector system.

165. A method for modifying a medical injector system comprising the steps of:

(i) replacing the syringe holder with a syringe holder according to claim 41

(ii) attaching a plunger according to claim 74.

174. A method for engaging a syringe holder according to claim 14 with a medical injector comprising the steps of;

(i) aligning the engaging portion of the syringe holder with a complimentary portion on the medical injector; and

(ii) engaging the syringe holder with the medical injector.

(iii) detecting a level of engagement between the syringe holder and the medical injector system.

175. A method for disengaging a syringe holder according to claim 14 from a medical injector comprising the steps of;

(i) disengaging the engaging portion of the syringe holder from the medical injector; and

(ii) removing the syringe holder from the medical injector

(iii) detecting a level of disengagement between the syringe holder and the medical injector system.

180. A method for modifying a medical injector system comprising the steps of:

(i) replacing the syringe holder with a syringe holder according to claim 42

(ii) attaching a plunger according to claim 74.

209. A medical injector system according to claim 183 comprising a syringe holder according to claim 1.

252. A method for engaging a syringe holder according to claim 14 with a medical injector according to claim 183, comprising the steps of;

(i) aligning the engaging portion of the syringe holder with a complimentary portion on the medical injector; and

(ii) engaging the syringe holder with the medical injector.

253. A method for engaging a syringe holder according to claim 252 comprising the further step of detecting a level of engagement between the syringe holder and the medical injector system.

254. A method for disengaging a syringe holder according to claim 14 from a medical injector according to claim 183, comprising the steps of;

(i) disengaging the engaging portion of the syringe holder from the medical injector; and

(ii) removing the syringe holder from the medical injector.

255. A method for disengaging a syringe holder according to claim 254 comprising the further step of detecting a level of disengagement between the syringe holder and the medical injector system.

265. A method for modifying a medical injector system comprising a syringe holder, comprising the steps of:

(i) replacing the syringe holder with a syringe holder according to claim 1

(ii) attaching a plunger according to claim 74.

266. A method for modifying a medical injector system comprising a syringe holder, comprising the steps of:

(i) replacing the syringe holder with a syringe holder according to claim 1

(ii) attaching a plunger according to claim 109.

267. A method for modifying a medical injector system comprising the steps of:

(i) replacing the syringe holder with a syringe holder according to claim 41

(ii) attaching a plunger according to claim 74.

268. A method for modifying a medical injector system comprising the steps of:

(i) replacing the syringe holder with a syringe holder according to claim 42

(ii) attaching a plunger according to claim 74.

43. A hub for a syringe for use with a medical injector system, comprising an outer surface adapted to slidingly engage with a barrel of the syringe, and an inner surface having a substantially annular engaging portion adapted to be releasably engaged by a plunger to permit the hub to be selectively withdrawn along the barrel by the plunger.

44. A hub according to claim 43 wherein the engaging portion defines a cavity.

45. A hub according to claim 43 wherein the engaging portion comprises a groove.

46. A hub according to claim 45 wherein the groove extends at least partially along the circumference of the inner surface of the hub.

47. A hub according to claim 43 wherein the engaging portion is a ridge.

48. A hub according to claim 43 wherein the inner surface of the hub is complementary in shape to an outer surface of the plunger.

49. A hub according to claim 48 wherein the inner surface comprises an interior hollow that contacts the plunger.

50. A hub according to claim 43 wherein the hub comprises a seal.

51. A hub according to claim 50 wherein the seal has an extended leading edge to increase the efficiency of the seal under pressure.

58. A hub according to claim 43 for use with a syringe according to claim 154.

60. A method of filling a syringe with medical fluid from a sealed vessel the syringe comprising a hub according to claim 43, comprising the steps of:

(i) elevating the front portion of the syringe relative to the back portion;

(ii) advancing a plunger to a position within the syringe corresponding to a predetermined patient dose;

(iii) controlling movement of the plunger in a sequence of forward and backward movements to expel air from the syringe and any attached tube into the vessel bottle, and draw the desired dose of fluid into the syringe.

61. A method of filling a syringe according to claim 60 further comprising the step of automatically restricting the direction of movement of the plunger depending on the orientation of the syringe.

62. A method of filling a syringe according to claim 61 wherein the plunger may move either forward or backward when oriented with its front portion elevated with respect to its back portion and only in the forward direction when oriented with the back portion elevated with respect to its front portion.

63. A method of injecting a patient using syringe comprising a hub according to claim 43 and a medical injector system comprising the steps of,

(i) engaging a plunger with a hub slidingly engaging the barrel of a syringe

(ii) driving the hub along the syringe barrel;

and

(iii) expelling fluid from the syringe into a patient.

65. A method for removing a syringe comprising a hub according to 43, from a syringe holder comprising the steps of;

(i) releasing the catch to unlock the syringe; and

(ii) withdrawing the syringe from the cradle member.

66. A method of connecting a syringe hub according to claim 43 to a plunger according to claim 74 comprising the steps of;

(i) introducing the plunger into a syringe barrel within which the hub is slidingly engaged and engaging the plunger with the inner surface of the hub; and

(ii) activating the plunger such that the retention member engages the engaging portion of the hub.

67. A method for hand filling a syringe comprising a hub according to claim 43 and a plunger according to claim 74 comprising the steps of;

(i) introducing the plunger into the syringe barrel and engaging the plunger with the inner surface of the hub;

(ii) activating the plunger such that the retention member engages the engaging portion of the hub; and

(iii) withdrawing the engaged hub along the syringe barrel whilst drawing liquid into the syringe.

69. A hub according to claim 43 for use with a plunger according to claim 74.

94. A plunger according to claim 74 for use with a syringe according to claim 154.

102. A method of connecting a syringe hub according to claim 43 to a plunger according to claim 74 comprising the steps of;

(i) introducing the plunger into a syringe barrel within which the hub is slidingly engaged and engaging the plunger with the inner surface of the hub; and

(ii) activating the plunger such that the retention member engages the engaging portion of the hub.

103. A method for hand filling a syringe comprising a hub according to claim 43 and a plunger according to claim 74 comprising the steps of;

(i) introducing the plunger into the syringe barrel and engaging the plunger with the inner surface of the hub;

(ii) activating the plunger such that the retention member engages the engaging portion of the hub; and

(iii) withdrawing the engaged hub along the syringe barrel whilst drawing liquid into the syringe.

154. A syringe for use with a medical injector system including the hub of claim 43.

156. A syringe for use with a medical injector system comprising a plunger according to claim 74 and a hub according to claim 43.

242. A syringe for use with a medical injector system comprising a plunger according to claim 74 and a hub according to claim 43.

243. A medical injector system according to claim 183 comprising a syringe according to claim 154.

64. A method for loading a syringe comprising a hub according to 43 into a syringe holder, comprising the steps of;

(i) inserting a syringe barrel in the cradle member such that the catch is displaced; and

(ii) allowing the catch mechanism to return into its biased position to engage the syringe and thereby retain the syringe in the cradle member.

74. A plunger for a syringe for use with a medical injector system, the syringe having a barrel and a hub slidingly engaging the barrel;

the plunger comprising a retention member adapted to releasably engage a substantially annular engaging portion on an inner surface of the hub to permit the hub to be selectively withdrawn along the barrel by the plunger.

59. A hub according to claim 43 for use with a syringe according to claim 155.

75. A plunger according to claim 74 wherein the retention member is mechanically and/or electrically releasably engaged with the hub.

76. A plunger according to claim 75 wherein the releasable engagement is at least partly actuated by a weight mechanism.

77. A plunger according to claim 74 wherein the releasable engagement is actuated by retraction of the plunger.

78. A plunger according to claim 74 wherein the retention member is biased away from engagement with the hub.

79. A plunger according to claim 74, wherein the retention member comprises an actuation member disposed at least partially within a bore defined in the plunger and a locking member is located at or adjacent one end of the retention member and/or plunger, the locking member being movable by the retention member into or out of engagement with the engaging portion of the hub.

80. A plunger according to claim 79 wherein the retention member comprises a cam.

81. A plunger according to claim 79 wherein the retention member comprises a cone.

82. A plunger according to claim 79, wherein the actuation member has a rod portion and a nose portion and the locking member is, in the unlocked position, located between the plunger and the nose portion.

83. A plunger according to claim 79 wherein the actuation member is movable longitudinally along the bore in the plunger.

84. A plunger according to claim 74 wherein the retention member comprises a pin.

85. A plunger according to claim 74 adapted for manual filling of the syringe.

86. A plunger according to claim 85 wherein the plunger is incapable of engaging the hub after the syringe has been used.

87. A plunger according to claim 86 wherein the plunger is sufficiently shorter than the barrel of the syringe such that it can not reach the hub when the hub is located at the front most portion of the syringe barrel.

95. A plunger according to claim 74 for use with a syringe according to claim 155.

96. A method of filling a syringe with medical fluid from a sealed vessel using a medical injector system, the system comprising a plunger according to claim 74, comprising the steps of:

(i) elevating the front portion of the syringe relative to the back portion;

(ii) advancing a plunger to a position within the syringe corresponding to a predetermined patient dose;

(iii) controlling movement of the plunger in a sequence of forward and backward movements to expel air from the syringe and any attached tube into the vessel bottle, and draw the desired dose of fluid into the syringe.

97. A method of filling a syringe according to claim 96 further comprising the step of automatically restricting the direction of movement of the plunger depending on the orientation of the syringe.

98. A method of filling a syringe according to claim 97 wherein the plunger may move either forward or backward when oriented with its front portion elevated with respect to its back portion and only in the forward direction when oriented with the back portion elevated with respect to its front portion.

99. A method of injecting a patient using medical injector system comprising a plunger according to claim 74 comprising the steps of;

(i) engaging a plunger with a hub slidingly engaging the barrel of a syringe

(ii) driving the hub along the syringe barrel; and

(iii) expelling fluid from the syringe into a patient.

100. A method for loading a syringe into a syringe holder in a medical injector system comprising a plunger according to 74, comprising the steps of;

(i) inserting the syringe barrel in the cradle member such that the catch is displaced; and

(ii) allowing the catch mechanism to return into its biased position to engage the syringe and thereby retain the syringe in the cradle member.

101. A method for removing a syringe from a syringe holder in a medical injector system comprising a plunger according to 74, comprising the steps of;

(i) releasing the catch to unlock the syringe; and

(ii) withdrawing the syringe from the cradle member.

105. A plunger according to claim 74 for use with a syringe comprising a hub according to 43.

155. A syringe for use with a medical injector system comprising a plunger according to claim 74.

244. A medical injector system according to claim 183 comprising a syringe according to claim 155.

109. A plunger for a syringe for use with a medical injector system, the syringe having a barrel and a hub slidingly engaging the barrel, the plunger comprising:

(i) a retention member adapted to releasably engage an engaging portion of the hub to permit the hub to be selectively withdrawn along the barrel by the plunger; and

(ii) a sensor to detect a level of engagement between the plunger and the hub.

70. A hub according to claim 43 for use with a plunger according to claim 109.

110. A plunger according to claim 109 wherein the sensor detects full engagement between the plunger and hub.

111. A plunger according to claim 109 comprising a light sensor.

112. A plunger according to claim 111 wherein the light sensor comprises a fibre optic cable.

113. A plunger according to claim 109 comprising a mechanical sensor.

114. A plunger according to claim 109 comprising an electromagnetic sensor.

115. A plunger according to claim 109 for use with a medical injector system according to claim 183.

116. A plunger according to claim 109 for use with a medical injector system according to claim 189.

117. A plunger according to claim 109 for use with a medical injector system according to claim 193.

118. A plunger according to claim 109 for use with a medical injector system according to claim 201.

119. A plunger according to claim 109 for use with a medical injector system according to claim 205.

120. A plunger according to claim 109 for use with a medical injector system according to claim 213.

121. A plunger according to claim 109 for use with a syringe according to claim 154.

122. A plunger according to claim 109 for use with a syringe according to claim 155.

123. A method of filling a syringe with medical fluid from a sealed vessel using a medical injector system, the system comprising a plunger according to claim 109, comprising the steps of:

(i) elevating the front portion of the syringe relative to the back portion;

(ii) advancing the plunger to a position within the syringe corresponding to a predetermined patient dose;

(iii) controlling movement of the plunger in a sequence of forward and backward movements to expel air from the syringe and any attached tube into the vessel bottle, and draw the desired dose of fluid into the syringe.

124. A method of filling a syringe according to claim 123 further comprising the step of automatically restricting the direction of movement of the plunger depending on the orientation of the syringe.

125. A method of filling a syringe according to claim 124 wherein the plunger may move either forward or backward when oriented with its front portion elevated with respect to its back portion and only in the forward direction when oriented with the back portion elevated with respect to its front portion.

126. A method of injecting a patient using medical injector system comprising a plunger according to claim 109 comprising the steps of;

(i) engaging a plunger with a hub slidingly engaging the barrel of a syringe

(ii) driving the hub along the syringe barrel; and

(iii) expelling fluid from the syringe into a patient.

127. A method for loading a syringe into a syringe holder in a medical injector system comprising a plunger according to 109, comprising the steps of;

(i) inserting the syringe barrel in the cradle member such that the catch is displaced; and

(ii) allowing the catch mechanism to return into its biased position to engage the syringe and thereby retain the syringe in the cradle member.

128. A method for removing a syringe from a syringe holder in a medical injector system comprising a plunger according to 109, comprising the steps of;

(i) releasing the catch to unlock the syringe; and

(ii) withdrawing the syringe from the cradle member.

129. A method of connecting a syringe hub according to claim 43 to a plunger according to claim 109 comprising the steps of;

(i) introducing the plunger into a syringe barrel within which the hub is slidingly engaged and engaging the plunger with the inner surface of the hub; and

(ii) activating the plunger such that the, retention member engages the engaging portion of the hub.

130. A method for connecting a syringe hub according to claim 129 further comprising the step of detecting a level of engagement between the plunger and the hub.

132. A plunger according to claim 109 for use with a syringe comprising a hub according to 43.

133. A plunger according to claim 109 for use with a device according to claim 136.

134. A plunger according to claim 109 for use with a sensing system according to claim 154.

135. A plunger according to claim 109 for use with a sensing system according to claim 166.

212. A medical injector system according to claim 183 comprising a plunger according to claim 109.

136. A device for manually filling a syringe for use with a medical injector system, the syringe having a barrel and a hub slidingly engaging the barrel, the device comprising a plunger and a retention member adapted to releasably engage an engaging portion of the hub to permit the hub to be selectively withdrawn along the barrel by the plunger.

71. A hub according to claim 43 for use with a device according to claim 136.

106. A plunger according to claim 74 for use with a device according to claim 136.

137. A device according to claim 136 wherein the retention member is mechanically and/or electrically releasably engaged with the hub.

138. A device according to claim 136 wherein the releasable engagement is at least partly actuated by a weight mechanism.

139. A device according to claim 136 wherein the releasable engagement is actuated by retraction of the plunger

140. A device according to claim 136 wherein the retention member is biased away from engagement with the hub.

141. A device according to claim 136, wherein the retention member comprises an actuation member disposed at least partially within a bore defined in the plunger and a locking member is located at or adjacent one end of the retention member and/or plunger, the locking member being movable by the retention member into or out of engagement with the engaging portion of the hub.

142. A device according to claim 141 wherein the retention member comprises a cam.

143. A device according to claim 141 wherein the retention member comprises a cone.

144. A device according to claim 141 wherein the actuation member has a rod portion and a nose portion and the locking member is, in the unlocked position, located between the plunger and the nose portion.

145. A device according to claim 136 wherein the retention member comprises a pin.

146. A device according to claim 136 wherein the plunger is incapable of engaging the hub after the syringe has been used.

147. A device according to claim 136 wherein the plunger is sufficiently shorter than the barrel of the syringe such that it can not reach the hub when the hub is located at the front most portion of the syringe barrel.

148. A device according to claim 136 for use with a medical injector system according to claim 183.

149. A device according to claim 136 for use with a syringe according to claim 154.

150. A device according to claim 136 for use with a syringe according to claim 155.

151. A method of connecting a syringe hub according to claim 43 to a device according to claim 136 comprising the steps of;

(i) introducing the device into a syringe barrel within which the hub is slidingly engaged and engaging the device with the inner surface of the hub; and

(ii) activating the device such that the retention member engages the engaging portion of the hub.

152. A method for hand filing a syringe comprising a hub according to claim 43 and a device according to claim 136 comprising the steps of;

(i) introducing the device into the syringe barrel and engaging the device with the inner surface of the hub;

(ii) activating the device such that the retention member engages the engaging portion of the hub; and

(iii) withdrawing the engaged hub along the syringe barrel whilst drawing liquid into the syringe.

153. A device according to claim 136 for use with a syringe comprising a hub according to 43.

228. A medical injector system according to claim 183 adapted for use with a device according to any one of claims 136.

157. A sensing system for use with a medical injector system comprising a sensing member to detect the presence of a syringe holder associated with the medical injector system.

72. A hub according to claim 43 for use with a sensing system according to claim 157.

107. A plunger according to claim 74 for use with a sensing system according to claim 157.

158. A sensing system according to claim 157 wherein the sensing member is a light sensor.

159. A sensing system according to claim 157 wherein the sensing member is a mechanical sensor.

160. A sensing system according to claim 157 wherein the sensing member is an electromagnetic sensor.

161. A sensing system according to claim 158 comprising a reflecting member to reflect light to the sensing member.

162. A sensing system according to claim 161 wherein the reflecting member is associated with the syringe.

182. A method for modifying a medical injector system comprising the step of adding a sensing system according to claim 157.

229. A medical injector system according to claim 183 comprising the sensing system of claim 157.

231. A medical injector system according to claim 205 comprising the syringe sensing system of claim 157.

269. A method for modifying a medical injector system comprising the step of adding a sensing system according to claim 157.

166. A sensing system for use with a medical injector system comprising a sensing member to detect the presence of a syringe in a syringe holder associated with the medical injector system wherein the sensing system is adapted for use with a removable syringe holder.

73. A hub according to claim 43 for use with a sensing system according to claim 166.

108. A plunger according to claim 74 for use with a sensing system according to claim 166.

167. A sensing system according to claim 166 wherein the sensing member detects a level of engagement between the syringe holder and the medical injector system.

168. A sensing system according to claim 166 wherein the sensing member is a light sensor.

169. A sensing system according to claim 166 wherein the sensing member is a mechanical sensor.

170. A sensing system according to claim 166 wherein the sensing member is an electromagnetic sensor.

171. A sensing system according to claim 168 comprising a reflecting member to reflect light to the sensing member.

172. A sensing system according to claim 171 wherein the reflecting member is associated with a biasing member adapted to partially eject the syringe from the syringe holder upon release of a catch.

173. A sensing system according to claim 172 wherein the reflecting member is associated with the syringe.

176. A method for loading a syringe into a syringe holder of a medical injector system comprising a sensing system according to claim 166 comprising the steps of;

(i) inserting the syringe barrel in a cradle of the syringe holder; and

(ii) sensing the presence of the syringe in the holder with a sensing member associated with the sensing system.

177. A method for removing a syringe, from a syringe holder of a medical injector system comprising a sensing system according to claim 166 comprising the steps of;

(i) withdrawing the syringe from the cradle member; and

(ii) sensing the absence of a syringe in the holder with a sensing member associated with the sensing system.

178. A method for removing a syringe from a syringe holder according to claim 177 further comprising the step of automatically retracting the plunger after withdrawal of the syringe.

179. A method for removing a syringe from a syringe holder according to claim 177 further comprising the step of restricting retraction of the plunger until the syringe has been withdrawn.

181. A method for modifying a medical injector system comprising the step of adding a sensing system according to claim 166.

230. A medical injector system according to claim 183 comprising the sensing system of claim 166.

232. A medical injector system according to claim 205 comprising the syringe sensing system of claim 166.

233. A medical injector system according to claim 205 comprising the sensing system of claim 167.

234. A medical injector system according to claim 232 wherein the sensing member communicates with the controller to modify operation of the injector system.

235. A medical injector system according to claim 234 wherein the communication enables movement of the plunger to either fill or expel fluid from the syringe.

236. A medical injector system according to claim 234 wherein the communication disables movement of the plunger.

237. A medical injector system according to claim 234 wherein movement of the plunger is disabled after use if the syringe has not been removed.

238. A medical injector system according to claim 234 wherein movement of the plunger is disabled before use if the syringe has not been engaged to a specified level.

239. A medical injector system according to claim 234 wherein movement of the plunger is disabled before use if the syringe holder has not been engaged to a specified level.

240. A medical injector system according to claim 234 wherein a signal is created if removal of the syringe is attempted at certain orientations of the syringe.

241. A medical injector system according to claim 240 wherein the signal is created if removal is attempted while the syringe is in a substantially vertical orientation.

270. A method for modifying a medical injector system comprising the step of adding a sensing system according to claim 166.

183. A medical injector system for injecting fluid from a syringe into a patient, the syringe having a barrel and a hub slidingly engaging the barrel the hub comprising an inner surface having an engaging portion adapted to be releasably engaged by a plunger

the injector system comprising:

(i) a plunger for driving the hub, the plunger comprising a retention member adapted to releasably engage the engaging portion of the hub; and

(ii) a syringe holder comprising;

a cradle member adapted to receive a barrel of the syringe; and

a pivotable catch to releasably lock the syringe in the cradle member.

52. A hub according to claim 43 for use with a medical injector system according to claim 183.

53. A hub according to claim 43 for use with a medical injector system according to claim 189.

54. A hub according to claim 43 for use with a medical injector system according to claim 193.

55. A hub according to claim 43 for use with a medical injector system according to claim 201.

56. A hub according to claim 43 for use with a medical injector system according to claim 205.

57. A hub according to claim 43 for use with a medical injector system according to claim 213.

88. A plunger according to claim 74 for use with a medical injector system according to claim 183.

89. A plunger according to claim 74 for use with a medical injector system according to claim 189.

90. A plunger according to claim 74 for use with a medical injector system according to claim 193.

91. A plunger according to claim 74 for use with a medical injector system according to claim 201.

92. A plunger according to claim 74 for use with a medical injector system according to claim 205.

93. A plunger according to claim 74 for use with a medical injector system according to claim 213.

184. A medical injector system according to claim 183 further comprising a positioning device located on the cradle member to locate one end of the syringe in a predetermined location in the cradle member.

185. A medical injector system according to claim 183 wherein the syringe holder comprises an engagement portion to enable simple releaseable engagement with a medical injector.

186. A medical injector system according to claim 185 wherein the engagement portion of the syringe holder comprises a locking member.

187. A medical injector system according to claim 185 wherein the locking member of the syringe holder comprises a slot.

188. A medical injector system according to claim 185 wherein the locking member of the syringe holder comprises a pin.

189. A medical injector system according to claim 183 further comprising:

(i) a tube adapted to be connected to syringe to conduct fluid into or out of the syringe; and

(ii) a connector to connect the tube to a vessel containing medical fluid and thereby enable withdrawal of the fluid from the vessel into the syringe wherein the connector comprises a hollow spike to create an aperture through a bung in the vessel upon piercing of the bung by the spike.

190. A medical injector system according to claim 189 wherein the connector further comprises:

(i) a male luer portion having a locking collar; and

(ii) a disengagement portion to enable permanent disengagement of the spike from the male luer portion.

191. A medical injector system according to claim 190 wherein the disengagement portion comprises a frangible neck.

192. A medical injector system according to claim 189 wherein the spike comprises a barbed portion to resist removal of the spike from the vessel.

193. A medical injector system according to claim 183 further comprising a clamp between the tube and a male luer connector of the syringe, the clamp being moveable into a locking thread of the male luer connector thereby clamping the tube to the male luer connector.

194. A medical injector system according to claim 193 wherein the clamp comprises a gripping portion to increase the grip between it and the tube.

195. A medical injector system according to claim 193 wherein the clamp comprises a gripping portion to increase the grip between it and the connector.

196. A medical injector system according to claim 193 wherein the clamp comprises a gripping portion to increase the grip between it and the tube and connector.

197. A medical injector system according to claim 194 wherein the gripping portion is barbed.

198. A medical injector system according to claim 194 wherein the gripping portion comprises a ridge.

199. A medical injector system according to claim 194 wherein the gripping portion comprises a screw thread.

200. A medical injector system according to claim 193 wherein the clamp is tamper evident.

201. A medical injector system according to claim 183 comprising a base member and a sensor to detect orientation of the syringe holder with respect to the base member.

202. A medical injector system according to claim 201 wherein the sensor detects the angle between the syringe holder and base member.

203. A medical injector system according to claim 183 further comprising a switch to automatically initiate or inhibit movement of the plunger in the barrel depending on its orientation.

204. A medical injector system according to claim 203 wherein the switch is activated by a weight mechanism.

205. A medical injector system according to claim 183 further comprising a controller to control the movement of the plunger.

206. A medical injector system according to claim 205 comprising a base member and a sensor to detect orientation of the syringe holder with respect to the base member.

207. A medical injector system according to claim 206 wherein the sensor detects the angle between the syringe holder and base member.

208. A medical injector system according to claim 205 wherein the controller is operable to move the plunger to test patency of an intravascular catheter connected via a tube to the syringe.

210. A medical injector system according to claim 183 comprising a hub according to claim 43.

211. A medical injector system according to claim 183 comprising a plunger according to claim 74.

213. A medical injector system according to claim 183 comprising a sensor to detect a level of engagement between the plunger and the hub.

214. A medical injector system according to claim 213 wherein the sensor detects full engagement between the plunger and hub.

215. A medical injector system according to claim 213 comprising a light sensor.

216. A medical injector system according to claim 215 wherein the light sensor comprises a fibre optic cable.

217. A medical injector system according to claim 213 comprising a mechanical sensor.

218. A medical injector system according to claim 213 comprising an electromagnetic sensor.

219. A medical injector system according to claim 205 comprising a sensor to detect a level of engagement between the plunger and the hub.

220. A medical injector system according to claim 219 wherein the sensor communicates with the controller to further control the movement of the plunger.

221. A medical injector system according to claim 220 wherein the communication enables engagement of the plunger and the hub without thereby moving the hub.

222. A medical injector system according to claim 220 wherein the communication enables releasable locking of the hub to the plunger.

223. A medical injector system according to claim 220 wherein the communication causes releasable locking of the hub to the plunger.

224. A medical injector system according to claim 220 wherein the communication enables detection of used syringes.

225. A medical injector system according to claim 224 wherein a signal is created if the sensor detects the hub at a position forward of its most retracted state.

226. A medical injector system according to claim 220 wherein the communication enables detection of errors.

227. A medical injector system according to claim 226 wherein a signal is created if the hub and plunger disengage prematurely.

248. A method of filling a syringe with medical fluid from a sealed vessel the syringe for use with a medical injector system according to claim 183, comprising the steps of:

(i) elevating the front portion of the syringe relative to the back portion;

(ii) advancing the plunger to a position within the syringe corresponding to a predetermined patient dose;

(iii) controlling movement of the plunger in a sequence of forward and backward movements to expel air from the syringe and any attached tube into the vessel bottle, and draw the desired dose of fluid into the syringe.

249. A method of filing a syringe according to claim 248 further comprising the step of automatically restricting the direction of movement of the plunger depending on the orientation of the syringe.

250. A method of filling a syringe according to claim 248 wherein the plunger may move either forward or backward when oriented with its front portion elevated with respect to its back portion and only in the forward direction when oriented with the back portion elevated with respect to its front portion.

251. A method of injecting a patient using a medical injector system according to claim 183 comprising the steps of;

(i) engaging the plunger with the hub;

(ii) driving the hub along the syringe barrel; and

(iii) expelling fluid from the syringe into a patient.

256. A method for loading a syringe into a syringe holder associated with a medical injector system according to claim 183, comprising the steps of;

(i) inserting the syringe barrel in the cradle member such that the catch is displaced; and

(ii) allowing the catch mechanism to return into its biased position to engage the syringe and thereby retain the syringe in the cradle member.

257. A method for removing a syringe, from a syringe holder associated with a medical injector system according to claim 183 comprising the steps of;

(i) releasing the catch to unlock the syringe; and

(ii) withdrawing the syringe from the cradle member.

258. A method for loading a syringe into a syringe holder of a medical injector system according to claim 183 comprising the steps of;

(i) inserting the syringe barrel in a cradle of the syringe holder; and

(ii) sensing the presence of the syringe in the holder with a sensing member associated with the sensing system.

259. A method for removing a syringe, from a syringe holder of a medical injector system according to claim 183 comprising the steps of;

(i) withdrawing the syringe from the cradle member; and

(ii) sensing the absence of a syringe in the holder with a sensing member associated with the sensing system.

260. A method for removing a syringe from a syringe holder according to claim 259 further comprising the step of automatically retracting the plunger after withdrawal of the syringe.

261. A method for removing a syringe from a syringe holder according to claim 259 further comprising the step of restricting retraction of the plunger until the syringe has been withdrawn.

262. A method for removing a syringe from a syringe holder according to claim 259 further comprising the step of prompting retraction of the plunger after the syringe has been withdrawn.

263. A method of connecting a syringe hub to a plunger using a medical injector system according to claim 183 comprising the steps of;

(i) introducing the plunger into a syringe barrel within which the hub is slidingly engaged and engaging the plunger with the inner surface of the hub; and

(ii) activating the plunger such that a retention member engages the engaging portion of the hub.

264. A method of connecting a syringe hub to a plunger according to claim 263 further comprising the step of detecting a level of engagement between the plunger and the hub.

245. A method of filling a syringe with medical fluid from a sealed vessel the syringe for use with a medical injector system comprising the steps of:

(i) elevating the front portion of the syringe relative to the back portion;

(ii) advancing a plunger to a position within the syringe corresponding to a predetermined patient dose;

(iii) controlling movement of the plunger in a sequence of forward and backward movements to expel air from the syringe and any attached tube into the vessel bottle, and draw the desired dose of fluid into the syringe.

246. A method of filing a syringe according to claim 245 further comprising the step of automatically restricting the direction of movement of the plunger depending on the orientation of the syringe.

247. A method of filling a syringe according to claim 245 wherein the plunger may move either forward or backward when oriented with its front portion elevated with respect to its back portion and only in the forward direction when oriented with the back portion elevated with respect to its front portion.

271. A syringe holder for a medical injector system substantially as herein described with reference to FIGS. 2, 18a to 18e, 20 to 23f and 36 to 42.

272. A hub for a syringe for use with a medical injector system substantially as herein described with reference to FIGS. 2 to 17, 18d, 18e, 19 to 23a, 24, 28, 37b and 38 to 42

273. A plunger for a syringe for use with a medical injector system substantially as herein described with reference to FIGS. 2c, 3 to 17, 19 to 23a, 37b and 38 to 40.

274. A device for manually filling a syringe for use with a medical injector system substantially as herein described with reference to FIGS. 2c, 3 to 17, 19 to 23a, 37b and 38 to 40.

275. A syringe for use with a medical injector system substantially as herein described with reference to FIGS. 2, 18d, 18e, 19 to 24, 28 to 33, 36 to 37b and 38 to 42.

276. A sensing system for use with a medical injector system substantially as herein described with reference to FIGS. 36 to 42.

277. A medical injector system substantially as herein described with reference to FIGS. 2 to 42