A medical device and method for parenteral administration of a medicament avoiding accidental intravascular injection

Abstract

The present invention discloses a medical device (100) and method for administration of a medicament in the body by performing drawing of blood for safety and subsequently administer a medicament The co-axial barrel-needle arrangement includes an internal needle (101) and an external needle (201), each equipped with a hollow angled bevel (101a, 201a) for precise detection of blood vessels and administration of medicament respectively at the same level. The device incorporates internal and external plungers (104, 204), internal and external hubs (103, 203), and finger flange (301) for efficient handling. The medical device (100) of the invention being capable of detecting the damage in blood vessels before the administration of medicament.

Description

[0001] A MEDICAL DEVICE AND METHOD FOR PARENTERAL ADMINISTRATION OF A MEDICAMENT AVOIDING ACCIDENTAL INTRAVASCULAR INJECTION

[0002] FIELD OF THE INVENTION:

[0003] The present invention relates to a medical device and method for parenteral administration of a medicament avoiding accidental intravascular injection. Particularly it relates to a medical device and method for administration of a medicament in the body by performing drawing of blood for safety and subsequently administering a medicament; both through separate channels to avoid inadvertent intravascular injection.

[0004] BACKGROUND OF THE INVENTION:

[0005] Syringes and needles are widely used in medicine, research, veterinary medicine, and the pharmaceutical industry. Conventional syringe designs involve a cylinder and plunger, and the process of administration of medicament or drawing of blood is achieved by manipulating the plunger. However, the conventional method presents challenges, especially during drawing of blood, requiring the use of both hands, leading to technical difficulties, potential pain for the subject, and increased risk of needle manipulation.

[0006] The conventional method necessitates a change of hands after insertion during the process of drawing of blood, introducing technical complexities and potential discomfort for the user. This procedural step entails exerting substantial force to pull the plunger and generate a vacuum, resulting in operational instability and the heightened risk of obtaining false negative results. This limitation emphasizes the importance of adopting an improved system that minimizes procedural challenges, enhances user comfort, and ensures comprehensive detection of possible vascular injuries. In addition, if the needle inadvertently punctures a blood vessel, the administration of the medicament cannot proceed at that specific point. Therefore, it is imperative to ensure that the vessel puncture is identified by drawing of blood before administration of medicament.

[0007] Various types of barrel-needle configured devices are known to the art. The prior art document US6972005B2 discloses a syringe assembly for administering a variety of fluids includes a syringe provided with a plurality of flow-isolated chambers, each of which is in flow communication with a respective lumen of a multi-lumen needle located downstream from the syringe. Each lumen is flow- isolated from the rest of the lumens and guides a respective one of the variety of fluids toward an outlet port formed in the needle so that the fluids mix with one another only upon exiting the outlet port.

[0008] Another prior art document WO2018230913A1 discloses an injection needle bar extended to suck the injection liquid in the container to the other end through an end of the attachment inserted into the injection liquid container; An injection needle bar extended to send the injection liquid in the syringe connected to the other end to the living body through one end inserted into the living body; It is formed between the other end of the injection needle bar and the other end of the injection needle bar, to inject the injection liquid sucked from the injection container through the injection needle bar into the syringe through the injection needle bar before injecting the injection liquid A hub cylinder coupled to the syringe barrel, the hub cylinder being separated into an injection needle bar hub and an injection needle bar hub before injection of the injection solution; And a filter mounted biased toward the injection needle bar at a portion where the hub cylinder is separated, to filter foreign substances introduced when the injection fluid is sucked from the injection container. Yet another prior art document CA2547297C discloses a method of injecting a first viscous fluid into a target tissue simultaneous with aspirating a second viscous fluid from the target tissue is disclosed. A surgical system is provided that is capable of supplying pneumatic pressure and vacuum. A first viscous fluid is injected into the target tissue using pneumatic pressure from the system. A mode of operation of the system is changed to provide vacuum and pneumatic pressure. The second viscous fluid is aspirated from the target tissue using vacuum from the system, and the pneumatic pressure remains substantially constant during aspiration.

[0009] The conventional barrel-needle configuration having the drawback such as, said configuration integrates both the blood-drawing and medicament-administration functions into a single device, typically at a singular endpoint. Consequently, in situations where the needle has entered a blood vessel and during the blood-drawing phase, the collected blood may inadvertently mix with the medicament, rendering the entire sample unusable for further medical procedures. This limitation underscores the critical need for a system that ensures the separation of blooddrawing and medicament-administration processes, enhancing procedural safety and preventing contamination.

[0010] The proposed medical device and method overcome the challenges in the known art by introducing a co-axial barrel-needle arrangement with separate internal and external needles, allowing for independent channels for drawing of blood and administration of medicament. The method involves inserting the external needle which encompasses the internal needle, creating a vacuum within the internal barrel for blood drawing, confirming the absence of blood to ensure safe administration of medicament, and subsequently administering the medicament through the external needle. The invention eliminates the need for increased force during pulling of the plunger to draw blood, increases true positive and true negative results, and enhances safety. In summary, the proposed medical device and method offer a safer, more efficient approach to parenteral administration of medicaments.

[0011] OBJECT OF THE INVENTION:

[0012] The principle object of the present invention is to overcome all the mentioned and existed drawbacks of the prior arts by providing a medical device and method for parenteral administration of a medicament avoiding accidental intravascular injection.

[0013] Another object of the present invention is to provide a medical device for parenteral administration of a medicament avoiding accidental intravascular injection that being capable of detecting of injury of the blood vessel and prevention of entry of the medicament in the blood vessel.

[0014] Yet another object of the present invention is to provide a medical device for parenteral administration of medicament avoiding accidental intravascular injection having a co-axial barrel-needle arrangement such as two needles and two barrels i.e. internal needle connected with internal barrel and external needle connected with the external barrel.

[0015] Yet another object of the present invention is to provide a medical device for parenteral administration of medicament avoiding accidental intravascular injection in which if the blood vessel has accidentally been punctured by the needle, which is detected by drawing of blood, the blood not being mixed with the medicament enabling the reuse of the medicament.

[0016] Yet another object of the present invention is to provide a medical device for parenteral administration of medicament avoiding accidental intravascular injection in which the administration of the medicament is performed when the needle has not inadvertently punctured a blood vessel and blood is not detected in the internal barrel. This stringent criterion ensures the utmost safety and precision in the administration process, aligning with the inventive goal of averting accidental intravascular injections.

[0017] Yet another object of the present invention is to provide a medical device for parenteral administration of medicament avoiding accidental intravascular injection having a separate channel for administration of medicament and drawing of blood processes.

[0018] Yet another object of the present invention is to provide a medical device for parenteral administration of medicament avoiding accidental intravascular injection having a low volume empty channel making it easy for the user to pull the plunger to create low pressure vacuum during drawing of blood which gives a higher rate of true positive result especially when inside a small blood vessel, also making it easy for the user and less painful for the patient.

[0019] SUMMARY OF THE INVENTION:

[0020] This summary is provided to introduce a selection of concepts in a simplified form that are further disclosed in the detailed description of the invention. This summary is not intended to identify key or essential inventive concepts of the claimed subject matter, nor is it intended for determining the scope of the claimed subject matter.

[0021] The present invention is all about a medical device for parenteral administration of a medicament.

[0022] The main aspect of the present invention is to provide a medical device for parenteral administration of a medicament avoiding accidental intravascular injection, wherein said medical device comprising a co-axial barrel-needle arrangement having two needles, an internal needle locked with an internal barrel by an internal hub and an external needle locked with an external barrel by an external hub. The internal plunger and an external plunger disposed inside said respective barrel, and configured to create pressure within said respective barrels; said internal plunger aligned with axis of said internal needle. The internal thumb grip provided at the proximal end of said internal plunger and an internal plunger stopper at the distal end of said internal plunger being connected in its outer diameter to internal barrel body in an airtight manner. The internal barrel further comprising an internal sleeve located near the proximal end of said internal barrel generating resistance and stopping the action of pulling of internal plunger stopper. The external plunger having three extensions, an external thumb grip provided at the proximal end of said external plunger, an external plunger stopper at the distal end of the said external plunger being connected in its outer diameter to the external barrel body as well as the internal barrel body at its inner diameter at a central aperture in an airtight manner. The internal needle, being of a smaller diameter has a pointed end for insertion and being coupled with said internal barrel configured to perform drawing of blood. The external needle, having a larger diameter as compared to said internal needle diameter, coupled with said external barrel being capable of administering the medicament, external needle encloses the internal needle as well as external barrel encloses the internal barrel. The finger flange provided at the proximal part of base of the internal barrel having three side apertures providing entry of said external plunger. The finger flange further comprising the central aperture which is provided for the entry of said internal plunger. The cap provided to close the needle; said cap having a diameter greater than the external barrel to facilitate easy entry of the needle and prevent needlestick injury to the user while applying the cap over the needle after the usage of the device.

[0023] Another aspect of the present invention is to provide a method for parenteral administration of a medicament avoiding accidental intravascular injection, wherein said method comprising following steps: a. placing the external needle which also encompasses the internal needle at any desired angle to the skin of patient and inserting it inside the body of patient up to desired distance; b. pulling the internal plunger away from the length of the internal needle along the internal thumb grip of the internal plunger with thumb and middle / index finger of the dominant hand wherein the pulling causes internal plunger stopper to move proximal, creating vacuum in the empty internal barrel causing entry of blood in the internal barrel if the internal bevel of the internal needle is in the blood vessel; said internal barrel having low volume and is empty being capable of creating a low pressure vacuum assisting the entry of blood into the internal barrel even from small blood vessels with low pressure; c. contacting the internal plunger stopper along internal sleeve generating resistance and stopping the action of pulling of internal plunger stopper at the distal part of the internal sleeve and maintenance of vacuum for a desired period of time by maintaining the pull on the internal plunger at that point; blood entering the internal barrel through the internal bevel if the internal bevel is in a blood vessel and no blood entering the internal barrel if the internal bevel is not in a blood vessel; which can be visually confirmed by the user as the external and internal barrel are both transparent; releasing the pull on the internal plunger after a positive or negative entry of blood; causing automatic recoil of the internal plunger stopper and internal plunger distally due to the vacuum created inside the internal barrel; d. when no blood enters the internal barrel, initiating administration of medicament by pushing the external plunger along the external thumb grip of the external plunger with thumb of dominant hand while the index and middle finger of the dominant hand rest on the distal surface of the finger flange moving the external plunger stopper towards the external hub generating pressure and causing movement of medicament from the external barrel through the external bevel at the desired site.

[0024] Another aspect of the present invention is to provide a method for parenteral administration of a medicament avoiding accidental intravascular injection, wherein the medicament requires to be administered at different single points, after insertion of the external needle in the body till the first point, the internal plunger is pulled to draw blood to check if the internal bevel is in the blood vessel at that point, in case of no entry of blood in the internal barrel which can be visually confirmed, the user administers the predetermined volume of medicament through the external bevel at the same point, then inserts / draws the needle in the required direction to reach the second point where the internal plunger is pulled again to draw blood to check if the internal bevel is in the blood vessel at that point, in case of no entry of blood in the internal barrel which can be visually confirmed, the user administers the predetermined volume of medicament through the external bevel at the same point, this process can be repeated at multiple points, the extensions of the external plunger being separate and not inter-connected inside the external barrel makes the internal barrel visible through the transparent external barrel even when drawing of blood is to be performed at a point when the volume of medicament is lesser than the full capacity of the external barrel and the external plunger stopper is at any point in the external barrel including the most distal point, hence the internal barrel is visible along with the internal plunger and internal plunger stopper at any given point, hence if blood enters the internal barrel the user can detect it visually.

[0025] BRIEF DESCRIPTION OF THE DRAWINGS:

[0026] The foregoing summary, as well as the following detailed description of the invention, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, exemplary constructions of the invention are shown in the drawings. Components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure.

[0027] FIG. 1 represents the exploded view of the medical device as disclosed in the present invention.

[0028] FIG.2 shows the arrangement of the medical device as disclosed in the present invention.

[0029] FIG. 3 to FIG. 6 shows the arrangement and details of the plunger as disclosed in present invention.

[0030] FIG. 7 to FIG. 9 shows the arrangement and details of the sleeve as disclosed in the present invention.

[0031] Fig. 10 shows the arrangement of the external thumb grip and internal thumb grip as disclosed in the present invention.

[0032] Fig. 11 and FIG. 12 shows the configuration of hub as disclosed in the present invention.

[0033] FIG.13 shows the needle configuration as disclosed in the present invention.

[0034] FIG. 14 shows the architecture of internal plunger stopper as disclosed in the present invention.

[0035] FIG.15 shows the architecture of external plunger stopper as disclosed in the present invention.

[0036] DETAILED DESCRIPTION OF THE INVENTION: Detailed embodiments of the present invention are disclosed herein, however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific functional and structural details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.

[0037] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one with ordinary skill in the art to which the invention belongs.

[0038] The present invention overcomes the aforesaid drawbacks of conventional medical device. The objects, features, and advantages of the present invention will now be described in greater detail. Also, the following description includes various specific details and is to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that: without departing from the scope and spirit of the present disclosure and its various embodiments there may be any number of changes and modifications described herein.

[0039] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It must also be noted that as used herein and in the appended claims, the singular forms "a", "an," and "the" include plural references unless the context clearly dictates otherwise. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, the preferred, systems are now described.

[0040] Throughout the invention, medical device (100) refers to a device for the parenteral administration of a medicament, specifically to prevent accidental intravascular injection.

[0041] Throughout the invention, drawing of blood refers to the process of aspiration, in which the blood flows into a syringe or medical device before administering an injection. The purpose of aspiration is to ensure that the needle is correctly positioned within the intended tissue and to verify that no blood indicative of vessel penetration is aspirated into the barrel. This precautionary step helps to avoid accidental intravascular injection, reducing the risk of complications or adverse reactions associated with the unintended delivery of medicament into the bloodstream. Aspiration is commonly performed in medical procedures to enhance the safety and precision of injections, particularly when targeting specific anatomical locations or administering medications.

[0042] Throughout the invention, "administration of medicament" refers to the process of delivering a medication or therapeutic substance through the parenteral route such as intramuscular route, subcutaneous route or any site where direct intravascular administration is to be avoided.

[0043] The main embodiment of the present invention is to provide a medical device (100) for parenteral administration of a medicament avoiding accidental intravascular injection, wherein said medical device (100) comprising: a co-axial barrel-needle arrangement having two needles (101, 201); an internal needle (101) locked with an internal barrel (102) by an internal hub (103) and an external needle (201) locked with an external barrel (202) by an external hub (203); an internal plunger (104) and an external plunger (204) disposed inside said respective barrel (102, 202), and configured to create the pressure within said respective barrels (102, 202); said internal plunger (104) aligned with axis of said internal needle (101); an internal thumb grip (105) provided at the proximal end of said internal plunger (104) and an internal plunger stopper (106) at the distal end of said internal plunger (104) being connected in its outer diameter to said internal barrel body in an airtight manner; said internal barrel (102) further comprising an internal sleeve (102a) located near the proximal end of said internal barrel (102) generating resistance and stopping the action of pulling of internal plunger stopper (106); said external plunger (204) having three extensions (204a); an external thumb grip (205) provided at the proximal end of said external plunger (204); an external plunger stopper (206) at the distal end of the said external plunger (204) being connected in its outer diameter to the external barrel body as well as the internal barrel body at its inner diameter at a central aperture (206b) in an airtight manner; said internal needle (101), being of a smaller diameter has a pointed end for insertion and being coupled with said internal barrel (102) configured to perform drawing of blood; said external needle (201), having a larger diameter as compared to said internal needle (101) diameter, coupled with said external barrel (202) being capable of administration of the medicament; external needle (201) encloses the internal needle (101) as well as external barrel (202) encloses the internal barrel (102); a finger flange (301) provided at the proximal part of base (302) of the internal barrel (102) having three side apertures (302a) providing entry of said external plunger (204); said finger flange (301) and said base (302) further comprising the central aperture (302b) which provided for the entry of said internal plunger (104); a cap (401) provided to enclose the needle; said cap (401) having a diameter greater than the external barrel (202) to facilitate easy entry of the needle (101, 201) and prevent needle- stick injury to the user while applying the cap (401) over the needle (101, 201) after the usage of the device.

[0044] As per detailed embodiment of the present invention is to provide a medical device (100) for parenteral administration of a medicament avoiding accidental intravascular injection having a coaxial barrel-needle arrangement which refers to an arrangement in which a needle (101, 201) is centrally positioned at the distal end of the barrel (102, 202) in a coaxial (aligned or parallel) manner. The needle (101, 201) is located in the central axis of the barrel (102, 202) and attached at the distal end, allowing for precise and controlled administration of fluids or medicament as well as to perform drawing of blood. The coaxial arrangement ensures that the needle (101, 201) is aligned with the central axis of the barrel (102, 202), minimizing the risk of misalignment and enhancing the precision and reliability of the device (100). The medical device (100) having an internal needle (101) and an external needle (201) locked with an internal barrel (102) and an external barrel (202) respectively. The internal barrel (102) which is transparent being located in the central vertical axis of said external barrel (202) which is transparent. The internal barrel (102) being attached to the external barrel (202) at the proximal base (302) in an airtight manner being capable of restricting the entry of air or medicaments from the external barrel (202) into said internal barrel (102) or the entry of air from internal barrel (102) into the external barrel (202), thereby keeping both barrels (102, 202) separate from each other; said external barrel (202) and internal barrel (102) can be cylindrical or rectangular.

[0045] As per detailed embodiment of the present invention, a well (103 a, 203a) being provided at the opening of said internal hub (103) and said external hub (203) respectively along with grooves in the tunnel just proximal to the well configured to accumulate adhesive to bond the needle (101, 201) and hub (103, 203) which being capable of providing more strength and preventing leakage. As per detailed embodiment of the present invention, an internal plunger stopper (106) having a central groove (106a) which being capable of attaching with the internal plunger (104), wherein design of the shape of a central groove (106a) corresponds to the shape of the distal part (104a) of the internal plunger (104) so as to provide a tight attachment as well as grip and allowing the movement of the internal plunger (104) along with internal plunger stopper (106) inside the internal barrel (102) as a single unit.

[0046] As per detailed embodiment of the present invention, external plunger stopper (206) having plurality of grooves (206a) which being capable of accommodating and gripping with the distal part (204b) of the extensions (204a) of the external plunger (204) wherein the shape of the grooves (206a) are corresponding to the shape of the distal part (204b) of the extensions (204a) so as to provide a tight attachment as well as grip and allowing the movement of the external plunger (204) along with external plunger stopper (206) inside the external barrel (202) as a single unit and the central aperture (206b) allows the internal barrel (102) to pass through the external plunger stopper (206). The distal part (204b) of the extensions (204a) of the external plunger (204) can be of any shape to fit in the respective grooves (206a) of the external plunger stopper (206) for a tight fit.

[0047] As per detailed embodiment of the present invention, the external plunger (204) having one or more longitudinal extensions (204a) extending from the external thumb grip (205) wherein the longitudinal extensions (204a) extend distally which can be fitted to respective said grooves (206a) of the external plunger stopper (206), wherein the longitudinal extensions (204a) are separate and not connected directly to each other inside the external barrel (202) in order to keep the internal barrel (102) along with the internal plunger (104) and internal plunger stopper (106) visible clearly through the transparent external barrel (202) especially during the movement of the external plunger (204) during administration of medicament. The longitudinal extensions (204a) can also be connected with each other. As per detailed embodiment of the present invention, the orientation, location, and the number of the extensions (204a) from the outer thumb grip (205) of said external plunger (204) depends on the selected arc angle of grooves (206a) of outer plunger stopper (206) which can be 90 degree, 120 degrees or 180 degrees.

[0048] As per detailed embodiment of the present invention, said external plunger stopper (206) having the one or more grooves (206a) corresponding to the number of extensions (204a) of the external plunger (204); wherein the grooves (206a) are located on the external plunger stopper (206) at the end points of the arc length proportional to an arc angle of 90 degrees, 120 degrees or 180 degrees uniformly along the entire circumference in order to generate uniform pressure.

[0049] As per detailed embodiment of the present invention, internal plunger (104) having a longitudinal extension extending from the internal thumb grip (105) wherein the longitudinal extension extends distally which can be fitted to said central groove (106a) of the internal plunger stopper (106).

[0050] As per detailed embodiment of the present invention, the length and gauge of external needle (201) is shorter and smaller than internal needle (101) respectively. The external needle (201) in this arrangement features a shorter length and smaller gauge compared to the internal needle (101). The external needle (201) having a gauge between the range of 18G to 24G and internal needle (101) having a gauge between the range of 30G to 34G.

[0051] As per detailed embodiment of the present invention, the medical device (100) allows a versatile selection of net volumes for both the external and internal barrels (102, 202), providing to diverse medical requirements. The net volume of the external barrel (202) can be selected from the expansive range of 1 cc to 100 cc, providing flexibility to accommodate a different dosage as per the end user requirement. The net volume of said internal barrel (102) can be selected from the range of 0.5 cc to 20 cc. As per detailed embodiment of the present invention, two thumb grip (105, 205) provided at the proximal end of respective plunger (104, 204). The internal plunger (104) having the internal thumb grip (105) provided at the proximal end of said internal plunger (104). The internal thumb grip (105) is configured at an obtuse angle relative to the internal plunger (104), reducing the force required for pulling and withdrawal of the internal plunger (104), facilitating user grip, and enhancing vacuum creation for a smoother blood-drawing process. The external plunger (204) having the external thumb grip (205) provided at the proximal end of said external plunger (204). The shape of said external thumb grip (205) can be selected but not limited to triangular, square, rectangle, or semicircle along with a central gap; particularly said external thumb grip (205) can be semicircle in shape with a gap in the centre to allow the movement of the internal plunger (104) and to avoid collision during movement with the internal thumb grip (105).

[0052] As per detailed embodiment of the present invention, said internal thumb grip (105) is of a shape to avoid collision during movement with said external plunger (204) and external thumb grip (205), shape of said internal thumb grip (105) can be but not limited to circular, oval, triangular, half oval, or half circle.

[0053] As per detailed embodiment of the present invention, barrels (102, 202) are attached to an internal needle (101) and an external needle (201) respectively, both equipped with a hollow angled bevel (101a, 201a). The internal needle (101) and external needle (201) having a hollow angle bevel for detection of puncture blood vessel and for administration of medicament respectively at the same level such as if said external bevel (201a) being in the blood vessel or tissue, said internal bevel (101a) also being inside the blood vessel or tissue respectively. The external bevel (201a) and internal bevel (101a) of said external needle (201) and said internal needle (101) respectively being arranged in a configuration that the length of said internal bevel (101a) being enclosed within the length of said external bevel (201a), said internal needle (101) travels for a longer length from the internal hub (103) so that both internal bevel (101a) and external bevel (201a) lie at the same plane. The bevel angle of both internal and external needles (101, 201) range from 0 degrees to 45 degrees and the second cut angle range is from 0 degrees to 45 degrees.

[0054] As per detailed embodiment of the present invention, solid base (302) attached distal to said finger flange (301) from which also consists of a base protruding sleeve (302c) at its circumference which attaches with a protruding sleeve (202a) at the proximal end of the external barrel (202) in an air-tight manner for assembly of the device as well as alignment of both barrels (102, 202) in the same axis where in the base protruding sleeve (302c) may also be present directly on the finger flange (301) in the absence of a solid base (302) to attach with the protruding sleeve (202a) of the proximal portion of the external barrel (202) in an air-tight manner. The protruding sleeve (202a) at the proximal end of the external barrel (202) with a circumference greater or similar to the circumference of the external barrel (202) which fixes over the base protruding sleeve (302c) sleeve at the circumference of the said solid base (302) for assembly of the device as well as alignment of both barrels (102, 202) in the same axis.

[0055] As per detailed embodiment of the present invention, the finger flange (301) may be mounted on the solid cylindrical base (302); said base (302) and finger flange (301) comprise of one or more openings wherein the extensions (204a) of the external plunger (204) pass longitudinally through the respective said apertures (302a); a central aperture (302b) wherein the internal plunger (104) extends longitudinally.

[0056] As per detailed embodiment of the present invention, method for parenteral administration of a medicament avoiding accidental intravascular injection, said method comprising following steps: a. placing the external needle (201) which also encompasses the internal needle (101) at any desired angle to the skin of patient and inserting it inside the body of patient up to desired distance; b. pulling the internal plunger (104) away from the length of the internal needle

[0057] (101) along the internal thumb grip (105) of the internal plunger (104) with thumb and middle / index finger of the dominant hand wherein the pulling causes internal plunger stopper (106) to move proximal, creating vacuum in the empty internal barrel (102) causing entry of blood in the internal barrel

[0058] (102) if the internal bevel (101a) of the internal needle (101) is in the blood vessel; said internal barrel (102) having low volume and is empty being capable of creating a low pressure vacuum assisting the entry of blood into the internal barrel (102) even from small blood vessels with low pressure; c. contacting the internal plunger stopper (106) along internal sleeve (102a) generating resistance and stopping the action of pulling of internal plunger stopper (106) at the distal part of the internal sleeve (102a) and maintenance of vacuum for a desired period of time by maintaining the pull on the internal plunger (104) at that point; blood entering the internal barrel (102) through the internal bevel (101a) if the internal bevel (101a) is in a blood vessel and no blood entering the internal barrel (102) if the internal bevel (101a) is not in a blood vessel; which can be visually confirmed by the user as the external and internal barrel (202, 102) are both transparent; releasing the pull on the internal plunger (104) after a positive or negative entry of blood; causing automatic recoil of the internal plunger stopper (106) and internal plunger (104) distally due to the vacuum created inside the internal barrel (102); d. when no blood enters the internal barrel (102), initiating administration of medicament by pushing the external plunger (204) along the external thumb grip (205) of the external plunger (204) with thumb of dominant hand while the index and middle finger of the dominant hand rest on the distal surface of the finger flange (301) moving the external plunger stopper (206) towards the external hub (203) generating pressure and causing movement of medicament from the external barrel (202) through the external bevel (201a) at the desired site. As per detailed embodiment of the present invention, the proximal pulling force being applied on the external thumb grip (205) being transmitted through the external plunger (204), creating the negative pressure inside the external barrel (202) and filling of external barrel (202) with the medicament before insertion of the device (100).

[0059] As per detailed embodiment of the present invention, shape of internal hub (103) is tapering distally as it extends distally towards the external hub (203).

[0060] As per detailed embodiment of the present invention, the medicament requires to be administered at different single points; after insertion of the external needle (201) in the body till the first point, the internal plunger (104) is pulled to draw blood to check if the internal bevel (101a) is in the blood vessel at that point, in case of no entry of blood in the internal barrel (102) which can be visually confirmed, the user administers the predetermined volume of medicament through the external bevel (201a) at the same point, then inserts / draws the needle in the required direction to reach the second point where the internal plunger (104) is pulled again to draw blood to check if the internal bevel (101a) is in the blood vessel at that point, in case of no entry of blood in the internal barrel (102) which can be visually confirmed, the user administers the predetermined volume of medicament through the external bevel (201a) at the same point, this process can be repeated at multiple points, the extensions (204a) of the external plunger (204) being separate and not interconnected inside the external barrel (202) makes the internal barrel (102) visible through the transparent external barrel (202) even when drawing of blood is to be performed at a point when the volume of medicament is lesser than the full capacity of the external barrel (202) and the external plunger stopper (206) is at any point in the external barrel (202) including the most distal point, hence the internal barrel (102) is visible along with the internal plunger (104) and internal plunger stopper (106) at any given point, hence if blood enters the internal barrel (102) the user can detect it visually. As per detailed embodiment of the present invention, the administration of a medicament is intended at a single point from external barrel (202) through external bevel (201a) and the drawing of blood being done by said internal barrel (102) through said internal bevel (101a) at that same end point, wherein only after no blood enters the internal barrel (102) through the internal bevel (101a), the medicament is administered at that point hence confirming that the external bevel (201a) is not in a blood vessel avoiding accidental intravascular injection since both bevels (102a, 202a) lie at the same level.

[0061] As per detailed embodiment of the present invention, if blood being detected in the internal barrel (102) through the punctured blood vessel during pulling of internal plunger (104) at a single point where administration of medicament is to be done at that same single point, the procedure is abandoned without administering the medicament; repeating the procedure at different or same site with same or different device as the medicament is not contaminated.

[0062] As per detailed embodiment of the present invention, the pulling or pushing force applied on said external thumb grip (205) being transmitted by the extensions (204a) of the external plunger (204) to the external plunger stopper (206) is uniform and without any air leak since the grooves (206a) of the external plunger stopper (206) being attached to the extensions (204a) are located at uniform circumferential points to generate uniform pressure.

[0063] As per detailed embodiment of the present invention, the force applied on said external thumb grip (205) being transmitted by the external plunger (204) causing the external plunger stopper (206) to move distally, which pushing said medicament inside the body of patient.

[0064] As per detailed embodiment of the present invention, the force applied to pull the internal plunger (104) in an empty separate internal barrel (102) of a smaller volume is lesser than the force required to pull the plunger of a medicament filled barrel to create vacuum for drawing of blood, hence the said device (100) making the process easier for the user in terms of ergonomics as well as improving safety by creating a low pressure vacuum facilitating entry of blood even from small vessels with low pressure hence leading to an increased true positive result, decreased false negative result and when the internal bevel (101a) is not in a blood vessel leading to increased true negative result.

[0065] As per detailed embodiment of the present invention, the desired time period for maintaining the pull of the internal plunger stopper (106) at the distal part of internal sleeve (102a) and maintenance of vacuum is at least 3 seconds up to 15 seconds to allow the blood to flow through the internal needle (101) which is of a higher gauge and longer length and so leads to slow flow of blood into the internal barrel (102) from all sizes of blood vessels.

[0066] As per detailed embodiment of the present invention, there is no contamination of the medicament in cases where there is a positive drawing of blood hence leading to less wastage and the medicament can be administered again.

[0067] Reference will now be made in detail to preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

[0068] Referring to Fig. 1 of the present invention, it shows the exploded view of the medical device (100). As shown in Fig. 1, the medical device (100) having a coaxialbarrel needle arrangement having two barrels (102, 202) and two needles (101, 201). The internal needle (101) locked with an internal barrel (102) by an internal hub (103) and an external needle (201) locked with an external barrel (202) by an external hub (203). The plurality of plunger (104, 204) being disposed inside the respective barrel (102, 202) configured to create the pressure within said respective barrel (102, 202). The thumb grip (105, 205) being provided at the proximal end of said plunger (104, 204) respectively and plunger stopper (106, 206) being provided at the distal end of said plunger (104, 204) respectively. The cap (401) provided to enclose the needle.

[0069] Referring Fig. 2 of the present invention, it shows the architecture of the arrangement of the medical device (100). The medical device (100) having two barrel i.e. internal barrel (102) and external barrel (202), two needles i.e. internal needle (101) and external needle (201). The internal barrel (102) being enclosed within said external barrel (202). The internal needle (101) being longer and having smaller diameter then external needle (201). The internal barrel (102) which is transparent being located in the central vertical axis of said external barrel (202) which is transparent. The internal barrel (102) being attached to the external barrel (202) at the proximal base (302) in an airtight manner being capable of restricting the entry of air or medicaments from the external barrel (202) into said internal barrel (102) or the entry of air from internal barrel (102) into the external barrel (202). The finger flange (301) configured to provide the proper grip at the time of operation.

[0070] Referring Fig. 3 to Fig. 6 represents the arrangement and details of the plunger (104, 204). The internal plunger (104) having internal thumb grip (105) at the proximal end and internal plunger stopper (106) at the distal end of said internal plunger (104). The external plunger (204) having external thumb grip (205) at the proximal end and external plunger stopper (206) at the distal end of said external plunger (204). The external plunger (204) having three extensions (204a) which being fitted in the grooves (206a) of the external plunger stopper (206). The internal barrel (102) being accommodated inside the central aperture (206b) of the external plunger stopper (206). The finger flange (301) having three apertures (302a) allows the extensions (204a) of the external plunger (204) to pass through. The finger flange (301) further comprising the central aperture (302b) allows the internal plunger (104) to pass through. Referring Fig. 7 to Fig. 9 of the present invention, representing the arrangement of the internal sleeve (102a), base protruding sleeve (302c) and protruding sleeve (202a). The base (302) attached distal to said finger flange (301) from which also consists of a base protruding sleeve (302c) at its circumference which attaches with a protruding sleeve (202a) at the proximal end of the external barrel (202) in an airtight manner for assembly of the device as well as alignment of both barrels (102, 202) in the same axis where in the base protruding sleeve (302c) may also be present directly on the finger flange (301) in the absence of a solid base (302) to attach with the protruding sleeve (202a) of the proximal portion of the external barrel (202) in an air-tight manner. The internal sleeve (102a) being located at the proximal end of internal barrel (102) generating resistance and stopping the action of pulling of internal plunger stopper (106).

[0071] Referring Fig. 10 of the present invention, it represent the arrangement of external thumb grip (205) and internal thumb grip (105) such as there is no collision between each of them during the movement.

[0072] Referring Fig. 11 to Fig. 12 of the present invention, the well (103a) has been strategically integrated at the opening of the internal hub (103) and well (203a) has been strategically integrated at the opening of the external hub (203) in conjunction with grooves in the tunnel, positioned just proximal to the well (103a, 203a). This design feature serves a dual purpose: firstly, the well (103a, 203a) provides a reservoir for adhesive, and secondly, the grooves are specifically configured to accumulate the adhesive, facilitating a robust bond between the needle (101, 201) and the respective hub (103, 203).

[0073] Referring Fig. 13 of the present invention, it shows the needle configuration. Fig. 13 clearly represents that, the external needle (201) is of a larger diameter with respect to the internal needle (101). The arrangement of the needle (101, 201) such as on a single point, drawing of blood and administration of medicament can be done. From the representation of Fig. 13, it is clear that both the internal needle (101) and the external needle (201) are equipped with a hollow angled bevel (101a, 201a) respectively. This specific arrangement feature serves a dual purpose: first, to facilitate the accurate detection of a puncture of a blood vessel, and second, to enable the precise administration of a medicament. Importantly, the positioning of these bevels ensures that if the external bevel (201a) is located within a blood vessel or tissue, the internal bevel (101a) is correspondingly situated inside the same blood vessel or tissue. The length of said internal bevel (101a) being lied within the length of said external bevel (201a), said internal needle (101) travels for a longer length from the internal hub (103) so that both internal bevel (101a) and external bevel (201a) lie at the same plane. This simultaneous alignment of the internal and external bevels (101a, 201a) at the same level enhances the efficiency and accuracy of the medical procedure, ensuring both detection of blood and administration occur precisely at the targeted site.

[0074] Referring Fig. 14 and Fig. 15 of the present invention, it shows the internal plunger stopper (106) and external plunger stopper (206) respectively. The internal plunger stopper (106) having central groove (106a) to accommodate the internal plunger (104). The external plunger stopper (206) having one central aperture (206b) which being capable of accommodating the internal barrel (102), and one or more grooves (206a) to accommodate the distal part (204b) of external plunger extensions (204a) in order to provide tight fixation. The external plunger stopper (206) having one or more grooves (206a) corresponding to the number of extensions (204a) of the external plunger (204); wherein the grooves (206a) are located on the external plunger stopper (206) at the end points of the arc length proportional to an arc angle of 90 degrees, 120 degrees or 180 degrees uniformly along the entire circumference in order to generate uniform pressure.

[0075] Without further description, it is believed that one of ordinary skill in the art can, using the preceding description and the illustrative examples, make and utilize the present invention and practice the claimed methods. It should be understood that the foregoing discussion and examples merely present a detailed description of certain preferred embodiments. It will be apparent to those of ordinary skill in the art that various modifications and equivalents can be made without departing from the spirit and scope of the invention.

[0076] LIST OF REFERENCE NUMERALS

[0077] Device (100)

[0078] Internal needle (101)

[0079] Internal bevel (101a)

[0080] Internal barrel (102)

[0081] Internal sleeve (102a)

[0082] Internal hub (103)

[0083] Internal plunger (104)

[0084] Distal part of internal plunger (104a)

[0085] Internal thumb grip (105)

[0086] Internal plunger stopper (106)

[0087] Central groove of internal plunger stopper (106a)

[0088] External needle (201)

[0089] External bevel (201a)

[0090] External barrel (202)

[0091] Protruding sleeve (202a)

[0092] External hub (203)

[0093] External plunger (204)

[0094] Extensions (204a)

[0095] Distal part of external plunger (204b)

[0096] External thumb grip (205)

[0097] External plunger stopper (206)

[0098] Grooves (206a) Central aperture (206b)

[0099] Finger flange (301)

[0100] Solid base (302)

[0101] Apertures (302a)

[0102] Central aperture (302b)

[0103] Base protruding sleeve (302c)

[0104] Cap (401)

Claims

Claims:I Claim,1. A medical device for parenteral administration of a medicament avoiding accidental intravascular injection, wherein said medical device (100) comprising: a co-axial barrel-needle arrangement having two needles (101, 201); an internal needle (101) locked with an internal barrel (102) by an internal hub (103) and an external needle (201) locked with an external barrel (202) by an external hub (203); an internal plunger (104) and an external plunger (204) disposed inside said respective barrel (102, 202), and configured to create the pressure within said respective barrels (102, 202); said internal plunger(104) aligned with axis of said internal needle (101); an internal thumb grip(105) provided at the proximal end of said internal plunger (104) and an internal plunger stopper (106) at the distal end of said internal plunger (104) being connected in its outer diameter to said internal barrel body in an airtight manner; said internal barrel (102) further comprising an internal sleeve (102a) located near the proximal end of said internal barrel (102) generating resistance and stopping the action of pulling of internal plunger stopper (106); said external plunger (204) having three extensions (204a); an external thumb grip (205) provided at the proximal end of said external plunger (204); an external plunger stopper (206) at the distal end of the said external plunger (204) being connected in its outer diameter to the external barrel body as well as the internal barrel body at its inner diameter at a central aperture (206b) in an airtight manner; said internal needle (101), being of a smaller diameter has a pointed end for insertion and being coupled with said internal barrel (102) configured to perform drawing of blood; said external needle (201), having a larger diameter as compared to said internal needle (101) diameter,coupled with said external barrel (202) being capable of administration of the medicament; external needle (201) encloses the internal needle (101) as well as external barrel (202) encloses the internal barrel (102); a finger flange (301) provided at the proximal part of base (302) of the internal barrel (102) having three side apertures (302a) providing entry of said external plunger (204); said finger flange (301) and said base (302) further comprising the central aperture (302b) which provided for the entry of said internal plunger (104); a cap (401) provided to enclose the needle; said cap (401) having a diameter greater than the external barrel (202).

2. The medical device for parenteral injection of a medicament avoiding accidental intravascular injection as claimed in claim 1, shape of internal hub (103) is tapering distally as it extends distally towards the external hub (203).

3. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein said internal barrel (102) which is transparent being located in the central axis of said external barrel (202) which is transparent, the internal barrel (102) being attached to the external barrel (202) at the base (302) in an airtight manner being capable of restricting the entry of air or medicaments from the external barrel (202) into said internal barrel (102) or the entry of air from internal barrel (102) into the external barrel (202), thereby keeping both barrels (102, 202) separate from each other; said internal barrel (102) can be cylindrical or rectangular.

4. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein said external plunger stopper (206) having plurality of grooves (206a) which being capable of accommodating and gripping with the distal part (204b) of the extensions (204a) of the external plunger (204) wherein the shape of thegrooves (206a) are corresponding to the shape of the distal part (204b) of the extensions (204a) so as to provide a tight attachment as well as grip and allowing the movement of the external plunger (204) along with external plunger stopper (206) inside the external barrel (202) as a single unit and the central aperture (206b) allows the internal barrel (102) to pass through the external plunger stopper (206).

5. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein the distal part (204b) of the extensions (204a) of the external plunger (204) can but not limited to ellipsoid, spherical, etc. to fit in the respective grooves (206a) of the external plunger stopper (206) for a tight fit.

6. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein said internal plunger stopper (106) having a central groove (106a) which being capable of attaching with the internal plunger (104), wherein the shape of the central groove (106a) corresponds to the shape of the distal part (104a) of the internal plunger (104) so as to provide a tight attachment as well as grip and allowing the movement of the internal plunger (104) along with internal plunger stopper (106) inside the internal barrel (102) as a single unit.

7. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein said external plunger (204) having one or more longitudinal extensions (204a) extending from the external thumb grip (205) wherein the longitudinal extensions (204a) extend distally which can be fitted to respective said grooves (206a) of the external plunger stopper (206), wherein the longitudinal extensions (204a) are separate and not connected directly to each other inside the external barrel (202) in order to keep the internal barrel (102) along with the internal plunger (104) and internal plunger stopper(106) visible clearly through the transparent external barrel (202) especially during the movement of the external plunger (204) during administration of medicament; said longitudinal extensions (204a) can also be connected with each other inside the external barrel (202).

8. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein said external plunger stopper (206) having one or more grooves (206a) corresponding to the number of extensions (204a) of the external plunger (204); wherein the grooves (206a) are located on the external plunger stopper (206) at the end points of the arc length proportional to an arc angle; said arc angle can be but not limited to 90 degrees, 120 degrees or 180 degrees uniformly along the entire circumference in order to generate uniform pressure.

9. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein the orientation, location, and the number of the extensions (204a) from the external thumb grip (205) of said external plunger (204) depends on the selected arc angle of grooves (206a) of external plunger stopper (206) which can be 90 degree, 120 degrees or 180 degrees.

10. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein said internal plunger (104) having a longitudinal extension extending from the internal thumb grip (105) wherein the longitudinal extension extends distally which can be fitted to said central groove (106a) of the internal plunger stopper (106).

11. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein the lengthand gauge of external needle (201) is shorter and smaller respectively than internal needle (101).

12. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein said external needle (201) having a gauge between the range of 18G to 24G and internal needle (101) having a gauge between the range of 30G to 34G.

13. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein the net volume of said external barrel (202) can be selected from the range of 1 cc to 100 cc.

14. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein the net volume of said internal barrel (102) can be selected from the range of 0.5 cc to 20 cc.

15. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein said internal thumb grip (105) is of a shape to avoid collision during movement with said external plunger (204) and external thumb grip (205), shape of said internal thumb grip (105) can be but not limited to circular, oval, triangular, half oval, or half circle.

16. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein the internal thumb grip (105) is configured at an obtuse angle relative to the internal plunger (104), reducing the force required for pulling and withdrawal of the internal plunger (104).

17. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein shape ofsaid external thumb grip (205) can be selected but not limited to triangular, square, rectangle, or semicircle along with a central gap; particularly said external thumb grip (205) can be semicircle in shape with a gap in the centre to allow the movement of the internal plunger (104) and to avoid collision during movement with the internal thumb grip (105); the shape of the outer thumb grip (205) can be selected corresponding to the orientation, number and location of the extensions (204a) which are further related to the arc angle of the grooves (206a) on the outer plunger stopper (206).

18. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein said internal needle (101) and external needle (201) having a hollow angled bevel (101a, 201a) at the distal end for detection of punctured blood vessel and for administration of medicament respectively at the same level such as if said external bevel (201a) being in the blood vessel or tissue, said internal bevel (101a) also being inside the blood vessel or tissue respectively.

19. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein the external bevel (201a) and internal bevel (101a) of said external needle (201) and said internal needle (101) respectively being arranged in a configuration that the length of said internal bevel (101a) being enclosed within the length of said external bevel (201a), said internal needle (101) travels for a longer length from the internal hub (103) so that both internal bevel (101a) and external bevel (201a) lie at the same plane.

20. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein said bevel angle of both internal and external needles (101, 201) range from 0 degrees to 45 degrees and the second cut angle range is from 0 degrees to 45 degrees.

21. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, said solid base (302) attached distal to said finger flange (301) from which also consists of a base protruding sleeve (302c) at its circumference which attaches with a protruding sleeve (202a) at the proximal end of the external barrel (202) in an air-tight manner for assembly of the device as well as alignment of both barrels (102, 202) in the same axis where in the base protruding sleeve (302c) may also be present directly on the finger flange (301) in the absence of a solid base (302) to attach with the protruding sleeve (202a) of the proximal portion of the external barrel (202) in an air-tight manner.

22. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, said protruding sleeve (202a) at the proximal end of the external barrel (202) with a circumference greater or similar to the circumference of the external barrel (202) which fixes over the base protruding sleeve (302c) at the circumference of the said solid base (302) for assembly of the device as well as alignment of both barrels (102, 202) in the same axis.

23. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein said finger flange (301) may be mounted on the solid cylindrical base (302); said base (302) and finger flange (301) comprise of one or more openings wherein the extensions (204a) of the external plunger (204) pass longitudinally through the respective said apertures (302a); a central aperture (302b) wherein the internal plunger (104) extends longitudinally.

24. The medical device for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 1, wherein a well (103 a, 203a) being provided at the opening of said internal hub (103) and said external hub (203) respectively along with grooves in the tunnel justproximal to the well configured to accumulate adhesive to bond the needle (101, 201) and hub (103, 203).

25. A method for parenteral administration of a medicament avoiding accidental intravascular injection, wherein said method comprising following steps: a. placing the external needle (201) which also encompasses the internal needle (101) at any desired angle to the skin of patient and inserting it inside the body of patient up to desired distance; b. pulling the internal plunger (104) away from the length of the internal needle (101) along the internal thumb grip (105) of the internal plunger (104) with thumb and middle / index finger of the dominant hand wherein the pulling causes internal plunger stopper (106) to move proximal, creating vacuum in the empty internal barrel (102) causing entry of blood in the internal barrel (102) if the internal bevel (101a) of the internal needle (101) is in the blood vessel; said internal barrel (102) having low volume and is empty being capable of creating a low pressure vacuum assisting the entry of blood into the internal barrel (102) even from small blood vessels with low pressure; c. contacting the internal plunger stopper (106) along internal sleeve (102a) generating resistance and stopping the action of pulling of internal plunger stopper (106) at the distal part of the internal sleeve (102a) and maintenance of vacuum for a desired period of time by maintaining the pull on the internal plunger (104) at that point; blood entering the internal barrel (102) through the internal bevel (101a) if the internal bevel (101a) is in a blood vessel and no blood entering the internal barrel (102) if the internal bevel (101a) is not in a blood vessel; which can be visually confirmed by the user as the external and internal barrel (202, 102) are both transparent; releasing the pull on the internal plunger (104) after a positive or negative entry of blood; causing automatic recoil of the internal plunger stopper (106)and internal plunger (104) distally due to the vacuum created inside the internal barrel (102); d. when no blood enters the internal barrel (102), initiating administration of medicament by pushing the external plunger (204) along the external thumb grip (205) of the external plunger (204) with thumb of dominant hand while the index and middle finger of the dominant hand rest on the distal surface of the finger flange (301) moving the external plunger stopper (206) towards the external hub (203) generating pressure and causing movement of medicament from the external barrel (202) through the external bevel (201a) at the desired site.

26. The method for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 25, wherein the proximal pulling force being applied on the external thumb grip (205) being transmitted through the external plunger (204), creating negative pressure inside the external barrel (202) and filling of external barrel (202) with the medicament before insertion of the device (100).

27. The method for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 25, wherein the medicament requires to be administered at different single points; after insertion of the external needle (201) in the body till the first point, the internal plunger (104) is pulled to draw blood to check if the internal bevel (101a) is in the blood vessel at that point, in case of no entry of blood in the internal barrel (102) which can be visually confirmed, the user administers the predetermined volume of medicament through the external bevel (201a) at the same point, then inserts / draws the needle in the required direction to reach the second point where the internal plunger (104) is pulled again to draw blood to check if the internal bevel (101a) is in the blood vessel at that point, in case of no entry of blood in the internal barrel (102) which can bevisually confirmed, the user administers the predetermined volume of medicament through the external bevel (201a) at the same point, this process can be repeated at multiple points, the extensions (204a) of the external plunger (204) being separate and not inter-connected inside the external barrel (202) makes the internal barrel (102) visible through the transparent external barrel (202) even when drawing of blood is to be performed at a point when the volume of medicament is lesser than the full capacity of the external barrel (202) and the external plunger stopper (206) is at any point in the external barrel (202) including the most distal point, hence the internal barrel (102) is visible along with the internal plunger (104) and internal plunger stopper (106) at any given point, hence if blood enters the internal barrel (102) the user can detect it visually.

28. The method for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 25, wherein administration of a medicament is intended at a single point from external barrel (202) through external bevel (201a) and the drawing of blood being done by said internal barrel (102) through said internal bevel (101a) at that same end point, where only after no blood enters the internal barrel (102) through the internal bevel (101a), the medicament is administered at that point hence confirming that the external bevel (201a) is not in a blood vessel avoiding accidental intravascular injection since both bevels (102a, 202a) lie at the same level.

29. The method for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 25, wherein if blood being detected in the internal barrel (102) through the punctured blood vessel during pulling of internal plunger (104) at a single point where administration of medicament is to be done at that same single point, the procedure is abandoned without administering the medicament; repeatingthe procedure at different or same site with same or different device as the medicament is not contaminated.

30. The method for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 25, wherein the pulling or pushing force applied on said external thumb grip (205) being transmitted by the extensions (204a) of the external plunger (204) to the external plunger stopper (206) is uniform since the grooves (206a) of the external plunger stopper (206) being attached to the extensions (206a) are located at uniform circumferential points to generate uniform pressure.

31. The method for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 25, wherein the force applied on said external thumb grip (205) being transmitted by the external plunger (204) causing the external plunger stopper (206) to move distally, which pushing said medicament inside the body of patient.

32. The method for parenteral administration of a medicament avoiding accidental intravascular injection as claimed in claim 25, wherein the desired time period for maintaining the pull of the internal plunger stopper (106) at the distal part of internal sleeve (102a) and maintenance of vacuum is at least 3 seconds up to 15 seconds to allow the blood to flow through the internal needle (101) which is of a higher gauge and longer length and so leads to slow flow of blood into the internal barrel (102) from all sizes of blood vessels.

Images