Injection system for suspension and solutions

An injection system for suspensions and solutions having five cartridges supported on a cartridge support. The cartridges are connected to a coalescing disc with five inlet passages and a single output passage with a feed line connected to the single passage. Suspensions and solutions supplied to the cartridges are selectively injected into a test subject by supplying a saline solution to the cartridge from a syringe pump through a selector which selects the cartridge to which the saline solution is supplied.

BACKGROUND OF THE INVENTION 
This invention relates to a system for injecting various suspensions and 
solutions into test subjects. 
In conducting various tests it is sometimes necessary to selectively inject 
different suspensions or solutions into a test animal. In some of these 
experiments it is necessary to remotely inject potentially hazardous 
materials, such as radioactive microspheres into test animals as in the 
determination of blood flow to various regions, organs or tissue and to 
measure cardiac output of animals exposed to gravitational forces in a 
centrifuge. In these experiments a system is needed to accomplish the 
multiple injections accurately and safely. 
BRIEF SUMMARY OF THE INVENTION 
According to this invention measured amounts of the different suspensions 
or solutions that are to be selectively injected into a test subject are 
located in a plurality of cartridges on a support. The cartridges are 
connected to a coalescing disc with an output line connected to the test 
subject. A syringe pump is provided to supply a measured amount of carrier 
solution to the cartridges through a sequencing device. One way valves are 
provided in the line between the solution reservoir and a three way 
connector and between the three way connector and the sequencing device. 
The syringe pump is connected to the third port of the three way connector 
.

DETAILED DESCRIPTION OF THE INVENTION 
Reference is now made to FIG. 1 of the drawing which shows an injection 
system 10 for selectively injecting measured amounts of different 
suspensions or solutions into a test subject, such as an animal on a 
centrifuge. 
The injection system includes a plurality of cartridges 12, with graduation 
markings, on a support member 14. In the device constructed the cartridges 
were 1 cc syringe barrels. The support member is secured to a plate member 
16. A plurality of one way stopcocks 20 are connected to the lower ends of 
cartridges 12. The stopcocks 20 are connected to a plurality of flexible 
tubes 21 leading to a coalescing disc 22. 
The coalescing disc has five input passages 23, connected to tubes 21, and 
a single output passage 24, connected to a supply line 26, leading to the 
test subject. A three way stopcock 28 is connected in the supply line 26 
adjacent output 24. 
A solution, such as heparinized saline solution, is selectively supplied to 
the cartridges 12, from a reservoir 30, by means of a syringe pump 32 and 
a sequencer 34. 
The syringe pump 32 is a conventional syringe pump used to provide a 
measured amount of solution to the cartridges 12. In the device 
constructed the syringe pump was a model 197 automatic injector Sage pump. 
The reservoir 30 is connected to the syringe pump 32 through a one way 
valve 36 and a three way connector 38. The syringe pump 32 is connected to 
the sequencer 34 through a three way stopcock 39, the three way connector 
38, two one way valves 40 and 42 and a three way stopcock 43. The one way 
valves 36 and 40 permit the syringe pump 32 to draw solution from 
reservoir 30 and to supply solution to the sequencer 34. The one way valve 
42 prevents any reverse flow in the line between the sequencer 34 and the 
syringe pump 32. 
The sequencer 34 includes a selector manifold 46 having an inlet passage 48 
and five output passages 50, shown in FIG. 5. A sequencer cylinder 52 fits 
into the selector manifold 46 and has a passage 54 for selectively 
connecting inlet passage 48 to one of the five output passages 50, as 
shown in FIG. 6. 
The sequencer cylinder 52 is stepped from one passage 50 to the next by a 
ratchet wheel 58 driven by a pawl 60, shown in FIGS. 3 and 4. The pawl 60 
is secured to a guide plate 62 and is held in engagement with the ratchet 
wheel 58 by a spring 64. A bolt 66 is secured to a cam wheel 68 and slides 
in slot 70 in guide plate 62 as the cam wheel rotates. This causes the 
guide plate to rotate around shaft 72 as the cam wheel rotates. As the 
guide plate rotates it moves the pawl against the ratchet wheel 58 to step 
the passage 54 from one passage 50 to the next for each rotation of cam 
wheel 68. The cam wheel 68 is driven by a motor 74 which is controlled as 
will be described with reference to FIG. 7. 
A remote control switch 76 is operated to close the circuit through relay 
78. This closes contacts 79 and 80 to supply power to the motor 74. As the 
motor starts to rotate cam wheel 68 closes the contacts of microswitch 82 
which maintains the energization of relay 78 when switch 76 is opened. The 
switch 82, after closing, is held closed for the remainder of one 
revolution of motor 74 by cam 68. When the cam step 84 passes the 
microswitch operating arm 86, the switch 82 is opened to stop the motor. 
When relay 78 is energized, in addition to starting motor 74, it also 
closes contacts 86 and 87 to close the charging circuit for braking 
capacitor 90 and opens contacts 91 and 92 to prevent the operation of the 
syringe pump during the stepping operation of the sequencer 34. The 
syringe pump can be operated either by closing switch 94 or by closing 
remote control switch 96. 
In the operation of the device the five three way stopcocks 18 and five one 
way stopcocks 20 are opened. A solution such as heparinized saline 
solution is supplied through three way stopcock 28 to fill the coalescing 
disc, lines and cartridges 12 to the zero mark of each cartridge. The five 
valves 20 are then closed and the five cartridges are filled with the 
desired microspheres suspension or other solution. This can be 
accomplished with the use of a loading device as described in our 
copending application "Microsphere Loading Device", Serial No. 929,469 
filed July 31, 1978. 
The three way stopcocks 18 are then closed and stopcocks 20 are opened. The 
lines from the sequencer are then connected to the stopcocks 18. After 
filling all the lines and bleeding all the air from the system with the 
use of three way stopcocks 18, 28, 39 and 43, the supply line 26 can be 
connected to the test subject in a conventional manner. All the stopcocks 
are then opened to permit flow through the system. 
The sequencer switch 76 is then operated to position the passage 54 in line 
with the first passage 50 in the sequencer. A marker 98 indicates the 
position of the sequencer. Switch 96 can then be operated to supply a 
measured amount of heparinized saline solution to the first cartridge to 
carry the microsphere suspension or solution in the first cartridge to the 
test animal. The sequencer is again operated to step the passage 54 to the 
second passage 50 with the above procedure being repeated until as many 
suspensions or solutions, up to five for the device constructed, have been 
injected into the test subject. A suspension or solution in any cartridge 
can be skipped by operating the selector without operating the pump. 
In the device constructed the ratchet wheel had 14 steps so that nine 
operations of the switch 76 are required to return the passage 54 to the 
first passage 50 after a complete cycle for the cartridges has been made. 
There is thus provided an apparatus for injecting various suspensions and 
solutions into test subjects.