Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
  • A61M5/178—Syringes
  • A61M5/31—Details
  • A61M5/315—Pistons; Piston-rods; Guiding, blocking or restricting the movement of the rod or piston; Appliances on the rod for facilitating dosing ; Dosing mechanisms
  • A61M5/31511—Piston or piston-rod constructions, e.g. connection of piston with piston-rod
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
  • A61M5/178—Syringes
  • A61M5/31—Details
  • A61M2005/3101—Leak prevention means for proximal end of syringes, i.e. syringe end opposite to needle mounting end
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
  • A61M5/178—Syringes
  • A61M5/31—Details
  • A61M2005/3103—Leak prevention means for distal end of syringes, i.e. syringe end for mounting a needle
  • A61M2005/3104—Caps for syringes without needle

Definitions

• the present invention relates to a medical device, particularly a medical syringe assembly for withdrawing body fluid, particularly blood, and collecting the blood specimen within the syringe which can be further used for sample analysis.
• This syringe is also effective in withdrawing blood as well as injecting drug like a conventional syringe.
• Blood serum is widely used to test the blood parameters in routine clinical practice and laboratory work.
• blood is withdrawn in the syringe by applying negative pressure and then forced into the vial by the application of positive pressure.
• a conventional syringe uses a simple pump consisting of a plunger that fits tightly in a tube, called barrel, wherein the plunger can be pulled and pushed allowing the syringe to take in and expel a fluid through an orifice at the open end of the barrel.
• the open end may be fitted with a hypodermic needle, a nozzle, or tubing to help direct the flow into and out of the barrel.
• the difficulty encountered in the use of conventional syringe is that the body fluid collection process is performed in two steps, i.e., firstly the blood is withdrawn in the syringe by application of negative pressure and then forced out into a container (vial or any other collection tube) by applying positive pressure.
• This two-step process exerts stress of negative and positive pressure on the blood cells (Erythrocytes and Leukocytes), and increases the probability of cell rupture, that may alter the properties of serum, due to mixing of intracellular content into extracellular fluid (serum), which is especially a concern for sensitive research work.
• This two-step process requires the use of syringe as well as a separate container for collection of blood specimen.
• US3937211 discloses a multi-purpose syringe for extracting a body fluid, storing the fluid and being adapted to be employed as the test vial for sealing purposes to a cap which has a spike extending into the passageway through which blood is drawn.
• a threaded end cover sealingly engages the rearward end of the vial and piston rod protrudes there through.
• the rod has at the forward end a piston head provided with a rearwardly extending sleeve which is placed into sealed locking engagement with the end cover after the specimen has been introduced or drawn into the vial.
• the combination of the cap at one end and the cover member at the other end provides a complete seal for the container.
• the piston rod has two portions which can be severed from each other.
• piston rod (plunger) is small with respect to the normal or convertible syringe shaft which makes the piston rod like a stick attached to a piston head.
• piston rod When the large portion of piston rod lies outside the barrel unsupported and the force is applied by the operator on the piston rod, it might make the rod prone to premature breakage or lead to needle displacement inside the vein or both.
• US 3937211 has no finger flanges, which further create problem of griping and holding inserted needle into a vein at stationary position while force is applied to move piston rod with respect to the vial.
• the stabilization of needle is a key feature of a syringe. Due to lack of grip and control on needle movement as well as the possibility of premature breakage of the piston rod inside the syringe, there is a likelihood of more pain due to multiple pricking and bleeding due to rupturing of vein.
• the present invention performs both the withdrawal and collection function in a single step within the same container while overcoming all the limitations existing in prior art.
• a convertible syringe is a device that is able to withdraw blood and thereafter converts into a container for blood specimen collection, transportation and any further analysis.
• a convertible syringe eliminates the positive pressure on the blood cell, thus decreases the chances of cell lysis.
• a convertible syringe assembly mainly comprises a barrel for collecting withdrawn fluid, a nozzle for providing a point of attachment for a needle, a plunger passing inside the barrel having a plurality of longitudinal spokes around the central axis of the plunger.
• a collapsible slot in at least one of the spokes allows lateral movement of plunger with respect to the central axis of convertible syringe and prohibits any resistive reactionary force to be exerted on the plunger to push it back towards the central axis of the barrel, thereby facilitating smooth removal of plunger from the barrel.
• the convertible syringe is sealed at the top by plunger cap and at the bottom by nozzle cap.
• the principal objective of the present invention is to provide a syringe assembly wherein withdrawal as well as collection of blood specimen is performed within the same container that can be further incubated and centrifuged for serum and plasma processing, thus eliminating the requirement of an additional container for collection of blood specimen.
• Yet another object of the invention is to provide a cost-effective and time-efficient single step mechanism of blood withdrawal, collection and transportation that maintains the quality of collected blood specimen by eliminating the possibility of contamination and coagulation of blood specimen.
• Yet another objective of the invention is to provide a collapsible slot for dislodging the plunger from barrel smoothly thereby converting the syringe into a vial.
• Yet another objective of the invention is to provide plurality of spokes that prevent lateral deviation of plunger inside the barrel.
• Yet another object of the invention is to provide stability to the needle of syringe with the help of flanges for strong griping. [0016] Yet another object of the invention is to provide a convertible syringe that allows redistribution of collected blood specimen.
• Fig. 1 illustrates components of convertible syringe assembly
• Fig. 1(a) illustrates parts of plunger
• Fig. 2 illustrates the process of removal of the plunger via collapsible slot
• FIG. 3 illustrates the forces applied along the central axis of plunger of the syringe DETAILED DESCRIPTION OF THE INVENTION
• Figure 1 shows a convertible syringe assembly (10) that mainly includes a barrel (101) and a plunger (102).
• the barrel (101) is a tube that has two ends- a tapered end (101a) and an open end (101b).
• a hollow tip i.e., a nozzle (103) is located at the tapered end (101a).
• the nozzle (103) provides the point of attachment for a needle ⁇ not shown here).
• the volume of collected blood specimen is indicated by graduation lines on the barrel (101). Graduation lines may be in milliliters or fractions of a milliliter, depending on the capacity of the convertible syringe (10). The larger the capacity, the larger the interval between graduation lines.
• the barrel (101) has plurality of flanges (104) on its opposite sides at the open end (101b) to provide strong gripping and stability to the needle of syringe at a single position during needle insertion into vein.
• the nozzle (103) is sealed by a cup-shaped hub (105), the latter being inside the nozzle cap (106).
• a cup-shaped hub (105) When the nozzle (103) of barrel (101) is inserted into a nozzle cap (106), the nozzle (103) slides into the hub (105) of nozzle cap (106).
• the nozzle cap (106) has screwing threads (106a) at the inner surface which sealingly engage with the screwing threads (101c) on the outer surface of the tapered end (101a) of the barrel (101). This helps to secure the seal between hub (105) of nozzle cap (106) and nozzle (103), especially inside the centrifuge, against centrifugal force.
• the base of the nozzle cap (106) is flat so that the convertible syringe (10) can be held in upright position without using any rack. For blood specimen serum separation, it is essential to keep the blood collection container upright (vertical) position.
• the plunger (102) is a piston-type rod that passes inside the barrel (101) through the open end (101b) of the barrel (101).
• the plunger (102) is divided into three parts- plunger seal (107), plunger shaft (108) and plunger top (109).
• Plunger seal (107) is the lowermost portion of the plunger (102).
• Plunger shaft (108) is the longitudinal portion between plunger seal (107) and plunger top (109).
• the plunger shaft (108) has plurality of longitudinal spokes (110) around the central axis (10a) of plunger (102) that prevent lateral deviation of the plunger (102) inside the barrel (101).
• the plunger (102) moves only in upward and downward direction, along the central axis (10a) of the syringe and maintains its ability to create pressure (negative and positive) inside the barrel (101).
• the plunger seal (107) maintains contact with the inner surface of barrel (101).
• the central axis (10a) of barrel (101) and that of plunger (102) coincide all the time so as to prevent any deviation of central axis (10a) of plunger (102) with respect to the central axis (10a) of barrel
• the plunger (102) is prevented from coming out of the barrel (101) by the circular rim (111) (see Figure 2) on the inner surface of barrel (101).
• the barrel (101) and nozzle cap (106) is designed in a way that the convertible syringe (10) could easily go through head of the regular centrifuge machine.
• At least one of the spokes (110) of the plunger (102) has a gap called "Collapsible Slot” (112) near the plunger seal (107) that allows lateral movement, i.e. tilting along the central axis (10a) of the plunger (102) with lateral force.
• Figure 1 (a) shows the lower margin (112a) of the collapsible slot that lies just above the plunger seal (107).
• the upper margin (112b) of the collapsible slot is just above the upper circular rim (11 la) of the barrel (101). This is an ideal length of the slot (112), but length of the slot (112) can vary and still be functional to dislodge the plunger (102).
• This increase in the distance between upper margin (112b) of collapsible slot (112) and upper circular rim (111a) of the barrel (101) affects the stability of plunger (102) inside the barrel (101).
• the plunger (102) can be dislodged by slot (112) of length up to 33% of plunger (102) length from the plunger seal (107).
• Plunger spoke (110) is a shelf-like structure that runs almost along the entire length of plunger shaft (108). The function of plunger spoke (110) is to stabilize plunger shaft (108) inside the barrel (101) from lateral deviation (tilting sideward) and allows only upward and downward movement of a plunger (102) and plunger seal (107).
• screwing threads (lOld) are present on the inner surface of barrel (101) to lock with the screwing threads (113a) that are present on the outer surface of the plunger cap (113) to prevent any spillage of blood specimen during handling.
• the container can now be used for transportation with the addition of anti-coagulants for further processing.
• Figure 3 shows the applied force (301) on the plunger by operator (nurses, technicians or doctors).
• the Y axis component (302) of applied force (301) causes upward and downward movement of plunger inside the barrel.
• the X axis component (303) of applied force (301) is a force perpendicular to the central axis (304) of plunger which tries to deviate plunger laterally inside the barrel. This lateral deviation is counter by reactionary force (305) from the barrel wall.
• X axis component (303) of applied force (301) results into lateral displacement of central axis (304) of plunger inside the barrel. This lateral deviation is prevented by spokes radiated from the hub of plunger. The lateral deviation of plunger spokes exerts force on the barrel, which is countered by reactionary force (305) from the barrel wall.
• the collapsible slot allows dis-balance between X axis component (303) of applied force (301) and reactionary force (305) from the barrel, at plunger convertible position inside the barrel.
• X axis component (303) of applied force (301) and reactionary force (305) from the barrel, at plunger convertible position inside the barrel.
• At convertible position when plunger seal hits the inward projected ring on the inner surface of syringe barrel, and at least one of the plunger spoke on the plunger shaft should have a gap (slot). At this position due to slot no reactionary force acts to counter lateral deviation of the plunger, and plunger easily come out from the barrel at this position.
• nozzle cap and barrel may be present to securely and sealingly engage with each other.
• screwing mechanism is used for locking
• screwing threads can be positioned at different places of the nozzle cap, barrel and plunger cap.
• different variations are possible in shape, size and design of nozzle and plunger cap.
• Umbilical Cord Blood inherently has higher tendency of clot formation than adult blood.
• total time duration of UCB collection is a major factor that decides the volume of UCB collected.
• the convertible feature of the present invention the total time taken for blood collection is reduced because blood is withdrawn and collected within the same container and thus the probability of maintaining large volume of collected UCB is increased. Therefore, in circumstances where blood from UCB is to be collected, the convertible syringe (10) is highly efficient.
• the convertible syringe (10) allows redistribution of collected blood specimen into other containers either by application of positive pressure or by application of gravitation flow technique where blood flows out of the container without exertion of positive pressure inside the barrel through plunger.
• the convertible syringe (10) applies controlled negative pressure while withdrawing blood from body.

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• Health & Medical Sciences (AREA)
• Vascular Medicine (AREA)
• Engineering & Computer Science (AREA)
• Anesthesiology (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Hematology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)

Applications Claiming Priority (2)

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Cited By (2)

Citations (2)

• 2015
  • 2015-09-18 IN IN2947DE2015 patent/IN2015DE02947A/en unknown
  • 2015-12-07 WO PCT/IB2015/059399 patent/WO2017046636A1/en active Application Filing

Patent Citations (2)

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