IMPLANTABLE ACCESS PORT WITH DOUBLE TANK

Abstract

A dual-reservoir access port includes a base having proximal and distal fluid reservoirs. Each fluid reservoir comprises a bottom wall and a side wall. A dual-barbed outlet stem projects from a distal end of the base and comprises a first barb and a second barb. A first fluid channel extends through the first barb to the distal reservoir, and a second fluid channel extends through the second barb to the proximal fluid reservoir. A puncture cover is disposed between at least a portion of the second fluid channel and the bottom of the distal fluid reservoir. A needle-penetrating septum is disposed above each fluid reservoir. A cap is placed over and around the base of the port, compressing and sealing the septa against the base. A locking collar can be placed over a dual-lumen catheter to lock the catheter to the dual-barbed outlet stem.

Description

ACCESS PORT TO IMPLANT WITH DOUBLE TANK CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority from U.S. provisional patent application N261 / 327,249, entitled “Implantable Dual Reservoir Access Port” and filed on April 23, 2010, the content of which is incorporated herein by reference. FIELD OF INVENTION The present invention relates to implantable access ports for the infusion of fluids to a patient and / or the removal of fluids from the patient and, more specifically, to vascular access ports with a dodgy reservoir. BACKGROUND OF THE INVENTION Implantable vascular access ports are widely used in the medical field to facilitate recurrent therapeutic procedures. A typical access port comprises a non-needle-penetrating housing containing a fluid reservoir sealed by a needle-penetrating septum. The access port also includes an outlet stem projecting from the housing, providing a fluid passage that communicates with the fluid reservoir. The outlet stem is used to connect the housing to a catheter. Specifically, the vascular access port connects to the proximal end of the catheter. The distal end of the catheter is placed in a blood vessel. The access port is typically implanted subcutaneously in an easily accessible location. Once the vascular access system is implanted, a non-profiled needle, such as a Huber needle, attached to a feeding line, can be used to access the implanted vascular access port by penetrating the septum, in order to administer the desired medication. Alternatively, body fluids can be removed from the location where the distal end of the catheter is placed. Many conventional access ports in use contain a single fluid reservoir through which medication can be administered to the patient. However, such structures can be very limiting for clinicians. For example, it is often desirable to administer medications that are incompatible when mixed in a single fluid reservoir before infusion into the patient's body. Alternatively, it may be desirable to use one lumen to administer medication to a patient and a second lumen to draw blood samples for analysis. In fact, some medical institutions have policies requiring that one lumen of an implantable port be dedicated to infusion and the other solely for blood sampling. Such multiple functions cannot be accomplished through the use of a single-reservoir access port. Conventional dual-reservoir access ports have been developed. A conventional dual-reservoir access port typically comprises a port base with two separate reservoirs formed within it: a central fluid reservoir and a lateral fluid reservoir. Each fluid reservoir has a corresponding access opening sealed by an individual septum. The individual septa are secured in place by a cap that engages with the port base. In some other designs, a single septum (e.g., a composite septum) may be used to seal both reservoirs. An outlet stem housing a pair of fluid passages projects from the outside of the port base. This outlet stem may be located between the pair of fluid reservoirs or at the distal end of the access port and in line with the dual fluid reservoir. When the outlet stem is positioned between the fluid reservoirs, the reservoirs are arranged side by side, and the outlet stem projects from a longitudinal side of the housing. This placement of the outlet stem causes the fluid reservoirs to be relatively far apart, increasing the overall size of the access port. During the implantation process for a conventional implantable access port with a single reservoir, a subcutaneous cavity is first created to receive and house the port. This is done by making an incision in the patient's skin at the desired implantation site. The access port is then inserted under the skin through the incision. The port's outlet stem is typically received within the cavity, and finally, the proximal end of the access port is positioned in the subcutaneous cavity. A catheter is then attached to the outlet stem of the access port. To implant a conventional side-by-side access port, an incision must be made at the implantation site that is at least as long as the access port. Only in this way can the access port be inserted through the incision, followed by the exit stem. The longer the incision, the longer the healing process before the access port can be used freely, and the greater the potential for infection and other complications. BRIEF DESCRIPTION OF THE INVENTION According to one aspect of the present invention, an access port base is provided comprising a proximal end, a distal end, a proximal fluid reservoir, a distal fluid reservoir, a double-barbed outlet stem projecting from the distal end of the access port base, a first fluid channel, a second fluid channel, and a puncture cover. The proximal fluid reservoir comprises a lower wall and is disposed at the proximal end of the access port base. The distal fluid reservoir comprises a lower wall and is disposed at the distal end of the access port base. The double-barbed outlet stem comprises a first barb comprising a first distal tip and a second barb comprising a second distal tip.The first fluid channel extends through the first barb and a first portion of the access port base, providing a first fluid path from the first distal tip of the first barb to the distal fluid reservoir. The second fluid channel extends through the second barb and a second portion of the access port base, providing a second fluid path from the second distal tip of the second barb to the proximal fluid reservoir. A first portion of the second fluid channel is disposed on the lower wall of the distal fluid reservoir, below the distal fluid reservoir. At least a portion of the puncture cover is disposed on the lower wall of the distal fluid reservoir between the distal fluid reservoir and the second fluid path. According to another aspect of the present invention, an access port is provided comprising a base, a first needle-penetrating septum disposed above a distal fluid reservoir of the base, a second needle-penetrating septum disposed above a proximal fluid reservoir of the base, and a cap securing the first and second needle-penetrating septa to the base. The base comprises a proximal end, a distal end, the proximal fluid reservoir, the distal fluid reservoir, a double-barbed outlet stem, a first fluid channel, a second fluid channel, and a puncture cover. The proximal fluid reservoir comprises a lower wall and is disposed at the proximal end of the base. The distal fluid reservoir comprises a lower wall and is disposed at the distal end of the base.The double-barbed outlet stem projects from the distal end of the base and comprises a first barb with a first distal tip and a second barb with a second distal tip. The first fluid channel extends through the first barb and a first portion of the base, providing a first fluid path from the first distal tip of the first barb to the distal fluid reservoir. The second fluid channel extends through the second barb and a second portion of the base, providing a second fluid path from the second distal tip of the second barb to the proximal fluid reservoir. A first portion of the second fluid channel is disposed in the lower wall of the distal fluid reservoir, below the distal fluid reservoir. At least a portion of the puncture cover is disposed in the lower wall of the distal fluid reservoir between the distal fluid reservoir and the second fluid path.The cap secures the first and second needle-penetrating septa to the base to form a fluid seal between the first septum and the distal fluid reservoir and between the second septum and the proximal fluid reservoir. The cap comprises a distal opening corresponding to the first needle-penetrating septum and the distal fluid reservoir, a proximal opening corresponding to the second needle-penetrating septum and the proximal fluid reservoir, and a lower skirt portion. According to yet another aspect of the present invention, an access port is provided comprising a base, a first needle-penetrating septum disposed above a distal fluid reservoir of the base, a second needle-penetrating septum disposed above a proximal fluid reservoir of the base, and a cap securing the first and second needle-penetrating septa to the base. The base comprises a proximal end, a distal end, the proximal fluid reservoir, the distal fluid reservoir, a double-barbed outlet stem, a first fluid channel, a second fluid channel, and a means for preventing puncture of the second fluid channel. The proximal fluid reservoir comprises a lower wall and is disposed at the proximal end of the base. The distal fluid reservoir comprises a lower wall and is disposed at the distal end of the base.The double-barbed outlet stem projects from the distal end of the base and comprises a first barb with a first distal tip and a second barb with a second distal tip. The first fluid channel extends through the first barb and a first portion of the base, providing a first fluid path from the first distal tip of the first barb to the distal fluid reservoir. The second fluid channel extends through the second barb and a second portion of the base, providing a second fluid path from the second distal tip of the second barb to the proximal fluid reservoir. A first portion of the second fluid channel is disposed in the lower wall of the distal fluid reservoir, below the distal fluid reservoir.The cap secures the first and second needle-penetrating septa to the base to form a fluid seal between the first septum and the distal fluid reservoir and between the second septum and the proximal fluid reservoir. The cap comprises a distal opening corresponding to the first needle-penetrating septum and the distal fluid reservoir, a proximal opening corresponding to the second needle-penetrating septum and the proximal fluid reservoir, and a lower skirt portion. BRIEF DESCRIPTION OF THE DRAWINGS For illustrative purposes, certain embodiments of the present invention are shown in the drawings. In the drawings, similar numbers indicate similar elements throughout. It should be understood, however, that the invention is not limited to the exact arrangements, dimensions, and instruments shown. In the drawings: Figure 1 is a detailed view of an exemplary embodiment of a dual-reservoir access port assembly comprising a dual-reservoir access port, a dual-lumen catheter, and a locking collar, according to an exemplary embodiment of the present invention; Figure 2 is a perspective view of the dual reservoir access port embodiment of Figure 1 in which the dual reservoir access port is assembled and attached to the dual lumen catheter by means of the locking collar, according to an exemplary embodiment of the present invention; Figure 3 is a cross-sectional view of the double-tank access port modality of Figure 1 taken along a sectional line AA illustrated in Figure 2, according to an exemplary modality of the present invention; Figure 4A is a cross-sectional view of the double-tank access port modality of Figure 1 taken along a sectional line CC illustrated in Figure 3, according to an exemplary modality of the present invention; Figure 4B is a cross-sectional view of the double-tank access port modality of Figure 1 taken along a sectional line DD illustrated in Figure 3, according to an exemplary modality of the present invention; Figures 4C-4G illustrate example cross-sectional views of additional embodiments of the double-tank access port of Figure 1 taken along the sectional line CC illustrated in Figure 3, according to an example embodiment of the present invention; Figure 5A is a cross-sectional view of the double-tank access port modality of Figure 1 taken along a sectional line EE illustrated in Figure 3, according to an exemplary modality of the present invention; Figure 5B is a cross-sectional view of the dual-reservoir access port embodiment of Figure 5A, further showing a puncture cover and a fluid path in dashed lines, according to an exemplary embodiment of the present invention; Figure 5C is a cross-sectional view of the double-tank access port modality of Figure 1 taken along a sectional line FF illustrated in Figure 3, according to an exemplary modality of the present invention; Figure 6 is a front view of a double-pronged outlet stem of the double-reservoir access port embodiment of Figure 1, according to an exemplary embodiment of the present invention; Figure 7A is another front view of the double-pronged outlet stem of the double-reservoir access port of Figure 1 from a GG line shown in Figure 6, according to an exemplary embodiment of the present invention; Figure 7B is a cross-sectional view of the double-pronged outlet stem of Figure 6 taken along a sectional line HH, according to an exemplary embodiment of the present invention; Figure 70 is a cross-sectional view of the double-pronged outlet stem of Figure 6 taken along a sectional line illustrated in Figure 7A, according to an exemplary embodiment of the present invention; Figure 8 is a cross-sectional view of the double-lumen catheter of Figure 1 taken along a sectional line BB illustrated in Figure 2, according to an exemplary embodiment of the present invention; Figure 9A is a side cross-sectional view of the double-lumen catheter and locking collar being prepared to be connected to the double-barbed outlet stem of the dual-reservoir access port of Figure 1, according to an exemplary embodiment of the present invention; Figure 9B is a side cross-sectional view of the catheter and locking collar attached to the double-barbed outlet stem of the dual-reservoir access port of Figure 1, according to an exemplary embodiment of the present invention; Figure 10A is a cross-sectional view of a modality of a septum used with the double-reservoir access port of Figure 1, according to an exemplary modality of the present invention; Figure 10B is an enlarged cross-sectional view of an assembled lid, septum, and base portion of the double-reservoir access port of Figure 1 indicated by portion J in Figure 4A, according to an exemplary embodiment of the present invention; Figure 11A illustrates an example perspective view of a further embodiment of the puncture cover of Figure 5B, according to an example embodiment of the present invention; Figure 11B illustrates an example cross-sectional view of an additional embodiment of the dual-reservoir access port of Figure 1 taken along a sectional line similar to AA illustrated in Figure 2. The cross-sectional view shows the puncture cover of Figure 11A disposed within the dual-reservoir access port, according to an example embodiment of the present invention; Figure 12A illustrates an example front view of a further example embodiment of a double-pronged outlet stem, according to an example embodiment of the present invention; Figure 12B illustrates an example planar front view of the example double-pronged outlet stem of Figure 12A of a sectional line KK illustrated in Figure 12A, according to an example embodiment of the present invention; and Figure 12C illustrates an example cross-sectional view of the example double-pronged outlet stem of Figure 12A taken along a sectional line LL illustrated in Figure 12B, according to an example embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION The terms proximal and distal refer to directions farther from or closer to, respectively, a physician implanting the access port assembly. Specific to this invention, the distal end of the example dual-reservoir access port refers to the end of the access port that connects to a catheter, and the proximal end of the catheter refers to the end of the catheter that connects to the access port assembly. A dual-reservoir access port (also referred to herein as a dual-reservoir port, access port, or implantable port) with an outlet stem arranged in line with its two fluid reservoirs has a distinct advantage in that the incision required for implantation is only as wide as the thickness of the access port, not its length. Furthermore, the in-line port design also provides improved cosmetics and aesthetics. Compared to a conventional side-by-side dual-reservoir access port, the in-line configuration of dual reservoirs presents challenges in arranging the internal fluid paths. Specifically, because the distal reservoir in an in-line dual-reservoir access port is located between the proximal reservoir and the outlet stem, the internal fluid paths must be carefully designed to connect the proximal reservoir to the outlet stem. A conventional in-line dual-reservoir access port typically uses an internal fluid path that loops around the distal reservoir. This fluid path around the distal reservoir is usually small and convoluted, which poses challenges for certain medical procedures. Figure 1 illustrates a detailed view of the elements of an exemplary embodiment of a dual-reservoir access port assembly, according to an exemplary embodiment of the present invention. The dual-reservoir access port assembly comprises a dual-reservoir port 100, a dual-barb outlet stem 200, a locking collar 300, and a dual-lumen catheter 400. The dual-reservoir port 100 further comprises a cap 110, two individual needle-penetrating septa 130, and a port base 150. The base of port 150 comprises a distal fluid reservoir 151 located at a distal end 160A of the base of port 150 and a proximal fluid reservoir 157 located at a proximal end 160B of the base of port 150. The distal reservoir 151 and the proximal reservoir 157 are generally cylindrical, each generally having a flat bottom wall 153, 159, and a side wall 152, 158, respectively. Alternatively, the reservoirs may be of any other shape, such as D-shaped, C-shaped, stadium-shaped, oval, triangular, rectangular, or trapezoidal. Additionally, the distal and proximal reservoirs 151, 157 may have different shapes. In the embodiment illustrated in Figure 1, the distal reservoir 151, the proximal reservoir 157, and the double-barbed outlet stem 200 are arranged in line with each other. The distal reservoir 151 and the proximal reservoir 157 are separated by a dividing wall 155.Preferably, the length of the dividing wall 155 is narrower than the maximum width of the distal reservoir 151 and the proximal reservoir 157, thereby creating a narrowed midsection 163 at the base of the port 150. The needle-penetrating septa 130 are positioned over the distal reservoir 151 and the proximal reservoir 157. In the particular embodiment shown, each of the individual septa 130 comprises an upper dome 131, an upper compression zone 139, a flange 133, and a lower plug 137. The upper dome 131 provides tactile feedback to a clinician regarding the center of the individual septum 130. The flange 133 comprises a ring of thin material disposed around the circumference of each of the septa 130. The flange 133 further comprises an upper surface 135 (illustrated in Figure 10A). The lower surface 136 of the flange 133 of each septum 130 is positioned on an upper surface 154 of the port base 150. The lower plug 137 of the flange 133 extends into a portion of the respective distal and proximal reservoirs 151 157.The outer diameter of the lower plug 137 is preferably slightly larger than the inner diameter of the distal and proximal reservoirs 151 157, so that when placed in the reservoirs, radial compression is achieved against the lower plug 137 of each of the septa 130. The lid 110 generally has an elongated dome shape and comprises a distal opening 111 at the distal end 170A of the lid 110, a proximal opening 113 located at the proximal end 170B of the lid 110, and a skirt 120. The distal opening 111 and the proximal opening 113 are generally circular and receive the upper domes 131 of the septum 130 for the distal and proximal reservoirs 151 and 157, respectively. The shape of the distal and proximal openings 111 ML / a / ZUZZ / UI 40^1 113 can also be adjusted to any alternative shape of the distal and proximal reservoirs 151, 157. The distal opening 111 and the proximal opening 113 are each surrounded by a ring, generally flat-top, 112A, 112B. The rings are separated by a spacer 114. The distal opening 111 and the proximal opening 113 also each have an inner side wall 115, 116. In the modality shown, the side walls 115, 116 are angled, i.e., the side walls 115, 116 generally have a truncated conical shape, surrounding a narrower upper opening and a wider lower opening. The inner side walls 115, 116 are in contact with an upper portion of the upper compression zone 139 of the individual septum 130. Cap 110 is placed over the individual septum 130 and the port base 150, engaging with the port base 150 via a locking mechanism to secure the septum 130 to the port base 150. In this particular embodiment, a number of receiving slots 161 are arranged on the outer side wall of the port base 150. The receiving slots 161 engage with locking flanges 162 (illustrated in Figures 4A and 4B) arranged on the corresponding inner wall of cap 110. When cap 110 is locked to the port base 150, it compresses the septum 130 against the port base 150, creating a fluid seal between the distal septum 130 and both the distal reservoir 151 and cap 110, and a fluid seal between a proximal septum 130 and both the proximal reservoir 157 as the cap 110. In one example embodiment, the cap 110 can be solvent-bonded to the base of the port 150. The skirt 120 generally follows the outer contour of the base of the port 150. The skirt 120 preferably also has a narrowed midsection 122 at approximately the midpoint of the implant port 100, corresponding to the narrowed midsection 163 at the base of the port 150. The narrowed midsection 122 of the skirt 120 provides the clinician with tactile feedback over the center of the implant port 100, thereby facilitating the identification of the distal reservoir 151 and the proximal reservoir 157. The skirt 120 preferably includes a plurality of suture holes 121 for suturing the implant port 100 to the surrounding tissue when implanted in a patient. The double-barbed outlet stem 200 is attached to the distal end 160A of the port base 150. The double-barbed outlet stem 200 comprises an upper barb 210 and a lower barb 220. The upper barb 210 and the lower barb 220 have a proximal base 230 that connects to the port base 150. The lower skirt portion 120 preferably includes an opening 125 to receive the proximal stem base 230 of the double-barbed outlet stem 200. The upper barb 210 and the lower barb 220 have a generally semicircular (D-shaped) cross-section and a slight taper towards their respective distal tips 216 and 226. The distal tips 216 and 226 form the distal tip of the double-barbed outlet stem 200. In one example embodiment, the stem of The double-pronged outlet 200 is integrally formed with the base 150. In another example embodiment, the double-pronged outlet stem 200 is formed separately from the base 150 and solvent-bonded to the base 150. The dual-barbed outlet stem 200 is designed to receive the dual-lumen catheter 400. The dual-lumen catheter 400 has a proximal end 430 that connects to the dual-barbed outlet stem 200. Each of the lumens of the dual-lumen catheter has an opening at the distal ends 410 and 420 of the catheter 400 lumens. The proximal end 430 of the catheter lumens is designed to fit over the upper and lower barbs 210 and 220 of the dual-barbed outlet stem 200. Each lumen of the 400 double-lumen catheter has a distal opening at the respective distal tips 410 and 420. In the configuration shown in Figure 1, the distal openings 410 and 420 are staggered. In this particular example, the distal tips 410 and 420 are produced by beveling, i.e., using a sharp instrument to remove a portion of the outer wall of a 400 double-lumen catheter lumen along the dividing wall, thereby creating staggered distal openings at the distal tips 410 and 420. Other catheter tip configurations, e.g., blunt tip, split tip, etc., and manufacturing techniques, such as cutting, welding, joining, etc., can be adapted to produce the distal catheter tips 410 and 420 of the 400 double-lumen catheter. Figure 2 illustrates a perspective view of the double-reservoir port 100 assembled and attached to the double-lumen catheter 400 by means of the locking collar 300, according to an exemplary embodiment of the present invention. During assembly, each of the septa 130 is placed in the respective reservoirs 151 and 157, and the cap 110 is placed over the septum 130 and locked into the base of the port 150, thereby compressing and securing the individual septum 130 between the base of the port 150 and the cap 110. The upper domes 131 of the individual septum 130 protrude from the distal opening 111 and the proximal opening 113 of the cap 110. The lower plugs 137 of the individual septum 130 protrude into a portion of the reservoirs 151 and 157. When the 400 double-lumen catheter is connected to the assembled dual-reservoir port 100, the proximal end 430 of the 400 double-lumen catheter slides onto the 200 double-barbed outlet stem, with the upper barb 210 positioned in one lumen and the lower barb 220 positioned in the other lumen of the 400 catheter. The locking collar 300 slides over the proximal end 430 of the 400 double-lumen catheter onto the 200 double-barbed outlet stem, thereby securing the 400 double-lumen catheter to the 200 double-barbed outlet stem. Figure 3 illustrates an example cross-sectional view of the double-reservoir port 100 taken along a sectional line AA illustrated in Figure 2, according to one example embodiment. As can be seen in Figure 3, the cap 110 fits into the base of the port 150, securing the single septum 130. The upper domes 131 of the septum 130 project from their respective distal opening 111 and proximal opening 113 of the cap 110. Figure 3 also illustrates that, for this particular embodiment, the double-barbed outlet stem 200 is constructed as a single piece with the base of the port 150, i.e., it is integrally formed with the base of the port 150. With reference to Figures 1 and 3 together, the upper barb 210 and the lower barb 220 of the double-barbed stem 200 are illustrated according to an exemplary embodiment of the present invention. An upper fluid channel 171 extends through the upper barb 210 and a portion 164A (illustrated in Figure 5A) of the port base 150 to provide a first upper fluid passage or path 173 (illustrated in Figure 5A) for fluid communication between the distal opening in the distal tip 216 of the upper barb 210 and the distal reservoir 151. The upper fluid channel 171 opens into the distal reservoir 151 at a proximal opening 218 in a lower portion of the side wall 152 of the distal reservoir 151 near the bottom 153 of the distal reservoir 151. A lower fluid channel 172 extends through the lower barb 220 and a portion 164B (illustrated in Figures 5B-5C) of the port base 150 to provide a second lower fluid passage or path 174 (illustrated in Figures 5B-5C) for fluid communication between the distal opening in the distal tip 226 of the lower barb 220 and the proximal reservoir 157. The lower fluid channel 172 opens into the proximal reservoir 157 at a proximal opening 228 in a lower portion of the side wall 158 of the proximal reservoir 157 and near the bottom 159 of the proximal reservoir 157. The upper barb 210 and lower barb 220, and the upper fluid channel 171 and lower fluid channel 172 are stacked vertically, i.e., one is positioned above the other, in the example configurations shown in Figures 1 and 3. Alternatively, the barbs of the double-barbed outlet stem 200 may be positioned horizontally or offset horizontally or vertically from one another. Portion 164B of the lower fluid channel 172 is located below the distal reservoir 151. The material between the bottom 153 of the distal reservoir 151 and the top of the lower fluid channel 172 is quite thin. Without the precautions described below, there is a perceived risk that a needle entering the distal reservoir 151 could pierce the lower fluid channel 172 and enter it, compromising fluid separation between the distal and proximal reservoirs 151 and 157. Figure 4A is a cross-sectional view of the double-tank access port modality of Figure 1 taken along a sectional line CC illustrated in Figure 3, IVIA / a / ZUZZ / UI 40^1 according to an exemplary embodiment of the present invention. Figure 4B is a cross-sectional view of the dual-reservoir access port embodiment of Figure 1 taken along a sectional line DD illustrated in Figure 3, according to an exemplary embodiment of the present invention. Figure 5A is a cross-sectional view of the dual-reservoir access port embodiment of Figure 1 taken along a sectional line EE illustrated in Figure 3, according to an exemplary embodiment of the present invention. Figure 5B is a cross-sectional view of the dual-reservoir access port embodiment of Figure 5A, further showing a puncture cover and a fluid path in bridged lines, according to an exemplary embodiment of the present invention.Figure 5C is a cross-sectional view of the double-tank access port modality of Figure 1 taken along a sectional line FF illustrated in Figure 3, according to an exemplary modality of the present invention. A cross-section of the upper fluid channel 171 is visible in Figure 4A. As illustrated in Figure 4A, the upper fluid channel 171 comprises a lumen 171.1 that generally has a semicircular cross-section 171.2, i.e., it has a semicircular or D-shaped lumen 171.1 along the entire length of the upper fluid channel 171. Because the upper fluid channel 171 forms the first upper fluid path 173, the fluid path 173 also comprises the lumen 171.1 with the generally semicircular cross-section 171.2 along the entire length of the fluid path 173. The cross-sections of the lower fluid channel 172 are illustrated in Figures 4A-4B. As illustrated in Figure 4A, the lower fluid channel 172 comprises a lumen 172.1 in a portion 164D (illustrated in Figure 5B) of the base 150. The lumen 172.1 has a generally semicircular cross-section 172.2 in the portion 164D. As illustrated in Figure 4B, the lower fluid channel 172 further comprises a lumen 172.3 in a portion 164B of the base 150 between the portion 164D and the proximal fluid reservoir 157. The lumen 172.3 has a generally semicircular cross-section 172.4 in this portion. It should be understood that the lower fluid channel 172 in this portion is the same as in portion 164E of the base 150E outside portion 164D between portion 164D and the distal tip 226. Therefore, the lower fluid channel 172 comprises the lumen 172.3 in portion 164E having a semicircular cross section 172.4. With reference to Figures 3, 4A, and 5B-5C together, an example puncture cover 140 is illustrated, according to an example embodiment of the present invention. Figure 4A illustrates an example cross-sectional view of the puncture cover 140 taken along the sectional line CC shown in Figure 3. As illustrated in Figure 4A, the puncture cover 140 comprises a lumen 140.1 that generally has a semicircular cross-section 140.2, i.e., it has a semicircular or D-shaped lumen 140.1 along the entire length of the puncture cover 140. Figures 5A-5B illustrate example cross-sectional views of the dual-reservoir access port 100 of Figure 1. As shown in these figures, at least a portion 144A of the puncture cover 140 is disposed within portion 164C of the lower fluid channel 172 directly below the bottom 153 of the distal reservoir 151 to protect against potential needle penetration into the lower fluid channel 172. The puncture cover 140 is also disposed between the bottom 153 of the distal fluid reservoir 151 and the second fluid path 174. It should be understood that the puncture cover 140 may extend through the lower fluid channel 172 beyond the walls 152 of the distal fluid reservoir 151, such as through portion 164D illustrated in Figures 5B-5C. In one example embodiment, the puncture cover 140 is a metal or metal alloy tube that lines at least portion 164C of the lower fluid channel 172 directly below the distal reservoir 151. It should be understood that the upper and lower fluid channels 171 and 172 may also have lumens 171.1, 172.1, and 172.3 with alternative shapes, such as circular, oval, C-shaped, elliptical, or stadium-shaped (rectangular with semicircular ends) cross-sections. It should also be understood that the puncture cover 140 may be of other sizes and shapes, such as C-shaped, stadium-shaped, oval, triangular, rectangular, or trapezoidal, to match the lumens 171.1, 172.1, and 172.3 if they are C-shaped, stadium-shaped, oval, triangular, rectangular, or trapezoidal. Further configurations of the puncture cover 140 are contemplated. With reference now to Figure 4C, a cross-sectional view of another example puncture cover, generally designated as 140a, according to an example embodiment of the present invention, is illustrated. The cross-section is taken along the sectional line CC shown in Figure 3. The puncture cover 140a is disposed at the base of the port 150 between the bottom 153 of the distal reservoir 151 and the lower fluid channel 172 to protect against the penetration of a needle into the lower fluid channel 172. The puncture cover 140a comprises a curved strip of material covering the upper portion of the lower fluid channel 172 at least in the portion 164C that lies below the bottom 153 of the distal reservoir 151. With reference now to Figure 4D, a cross-sectional view of another example puncture cover, generally designated as 140b, according to an example embodiment of the present invention, is illustrated. The cross-section is taken along line CC shown in Figure 3. The puncture cover 140b is disposed at the base of the port 150 between the bottom 153 of the distal reservoir 151 and the lower fluid channel 172 to protect against IVIA / a / ZUZZ / UI WiJI penetration of a needle into the lower fluid channel 172. The puncture cover 140b comprises a flat strip of material covering the upper part of the lower fluid channel 172 at least in the portion 164C that is below the bottom 153 of the distal reservoir 151. With reference now to Figure 4E, a cross-sectional view of another example puncture cover, generally designated as 140c, according to an example embodiment of the present invention, is illustrated. The cross-section is taken along line CC shown in Figure 3. The puncture cover 140c is disposed at the base of port 150 below the bottom 153 of the distal reservoir 151 to protect against needle penetration into the lower fluid channel 172. The puncture cover 140c comprises a tube of material surrounding the lower fluid channel 172 at least in the portion 164C that lies below the bottom 153 of the distal reservoir 151. With reference now to Figure 4F, a cross-sectional view of another example puncture cover, generally designated as 140d, is illustrated, according to an example embodiment of the present invention. The cross-section is taken along line CC shown in Figure 3. The puncture cover 140d is disposed in the bottom 153 of the distal reservoir 151 to protect against needle penetration into the lower fluid channel 172. Specifically, the puncture cover 140d is a material lining the bottom 153 of the distal reservoir 151. In one example embodiment, the puncture cover 140d is generally circular. With reference now to Figure 4G, a cross-sectional view of another example puncture cover, generally designated as 140e, according to an example embodiment of the present invention, is illustrated. The cross-section is taken along line CC shown in Figure 3. The puncture cover 140c is disposed at the base of the port 150 below the bottom 153 of the distal reservoir 151 to protect against needle penetration into the lower fluid channel 172. The puncture cover 140e comprises a disc of material covering the upper portion of the lower fluid channel 172 at least in the portion 164C that lies below the bottom 153 of the distal reservoir 151. In the puncture cover embodiments shown in Figures 3, 4A, and 4C-4G, the puncture covers are formed from a material that is harder than the material forming the base of the port 150. More preferably, the material is one that, at a thin thickness, would withstand the penetration of an infusion needle. In one example embodiment, titanium is used for the construction of the puncture cover 140 and 140a-e. In the examples shown, the titanium puncture cover is approximately 0.0127 centimeters thick. Other metals or metal alloys, for example, stainless steel, may also be suitable for constructing the puncture cover. The puncture covers shown in Figures 3, 4A, and 4C-4G are for preventing penetration into the lower fluid channel 172 by an infusion needle accessing the distal reservoir 151. The use of a puncture cover allows for a minimal distance between the bottom 153 of the distal reservoir 151 and the top of the lower fluid channel 172, resulting in a low overall profile for the dual-reservoir access port 100, according to an exemplary embodiment of the present invention. In the embodiment shown in Figures 3 and 4A, this distance is approximately 0.0508 centimeters. The resulting dual-reservoir access port 100 has an overall height similar to that of a low-profile, single-reservoir access port. With reference again to Figure 4A, the arrangement of the cap 110, the port base 150, and the single septum 130 is also illustrated. The cap 110 fits into the port base 150, compressing the single septum 130 to effect a fluid seal. The receiving grooves 161 along the outer wall of the port base 150 engage with the locking flanges 162 on the corresponding inner surface of the cap 110, providing a locking mechanism in this embodiment. Figure 4B also illustrates the receiving grooves 161 along the outer wall of the port base 150; these grooves 161 engage with the locking flanges 162 on the corresponding inner surface of the cap 110 to provide the locking mechanism. Figure 5A illustrates an example view of a cross-section of the double-tank access port 100 taken along the sectional line EE illustrated in Figure 3, according to an example embodiment of the present invention. As illustrated in Figure 5A, the upper fluid channel 171 extends from the distal tip 216 of the upper prong 210 of the stem 200 through portion 164A of the base 150 and into the distal reservoir 151. The upper fluid channel 171 opens into the distal reservoir 151 through the opening 218 in the distal side of the side wall 152 of the reservoir 151. As shown in Figure 5A, the upper fluid channel 171 provides a first upper fluid path 173 from the distal tip 216 of the upper prong 210 of the stem 200 through portion 164A of the base 150 and into the distal reservoir 151. Figure 5B illustrates an example view of a cross-section of the dual-reservoir access port 100, also taken along the sectional line EE illustrated in Figure 3, according to an example embodiment of the present invention. The view in Figure 5B differs from that in Figure 5A because the lower fluid channel 172 and puncture cover 140 are illustrated in Figure 5B with dashed lines. The lower fluid channel 172 and puncture cover 140 are shown with dashed lines to indicate that they are located below the bottom 153 of the distal fluid reservoir 151. Specifically, portion 164C of the fluid channel 172 and the puncture cover 140 are located directly below the distal reservoir 151. The lower fluid channel 172 opens into the proximal reservoir 157 through the opening 228 on the distal side of the lateral wall 158 of the reservoir 157. Figure 5C illustrates an example view of a cross-section of the double-reservoir port 100 taken along the sectional line FF illustrated in Figure 3, according to an example embodiment of the present invention. As illustrated in Figure 5C, the lower fluid channel 172 extends from the distal tip of the lower prong 226 of the stem 200 through portion 164B of the base 150 and into the distal reservoir 157. The lower fluid channel 172 opens into the proximal reservoir 157 through the opening 228 in the distal side of the side wall 158 of the reservoir 157. At least two embodiments are contemplated for the puncture cover 140 disposed within the lower fluid channel 172. In one embodiment, the portion 164D of the lower fluid channel 172 in which the puncture cover 140 is disposed is notched so that the internal lumen 140.1 of the puncture cover 140 has the same cross-section 140.2 as the cross-section 172.4 of the internal lumen 172.3 of the lower fluid channel 172 in portion 164E. The fluid channel 172 outside portion 164D and the lumen 140.1 of the puncture cover 140 together form the second lower fluid path 174 comprising a lumen 174.1 with a cross-section 174.2. In this mode, the cross-section 174.2 of the effective fluid channel 174 is the same at all points between the distal tip 226 and the opening 228. Figures 5B and 5C illustrate this arrangement. As shown in the figures, the cross-section 172.2 of the lumen 172.1 of the fluid channel 172 in portion 164D is excessively large to accommodate the puncture cover 140 lining the fluid channel 172 in portion 164D. The cross-section 172.4 of the lumen 172.3 of the fluid channel 172 outside portion 164D is equal to the cross-section 140.2 of the lumen 140.1 of the puncture cover 140; that is, the cross-section 174.2 of the lumen 174.1 of the fluid path 174 remains constant along its entire length. In another embodiment, the lower fluid channel 172 does not contain notches in portion 164D. Therefore, cross-section 172.2 is the same as cross-section 172.4. The cross-section of the lower fluid channel 172 is constant along all lengths of the lower fluid channel 172 from the distal tip 226 to the opening 228. The puncture cover 140 fits into the lower fluid channel 172. Therefore, the cross-section 140.2 of the lumen 140.1 of the puncture cover 140 is smaller than cross-sections 172.2 and 172.4. The lumen 174.1 of the second lower fluid path 174 narrows in portion 164D such that the cross-section 174.2 of the second lower fluid path 174 is smaller. IVIA / a / ZUZZ / UI 40^1 narrows in portion 164D than cross section 172.4. When implanted in a patient, either or both of the reservoirs in the dual-reservoir port 100 can be accessed externally through a non-profiled needle, for example, a 500 needle illustrated in Figure 11B. The infusion needle used to penetrate the needle-penetrating single septum 130 is typically the type known as a Huber needle. Due to its self-sealing nature, the single septum 130 can withstand repeated penetration by such an infusion needle without leakage. Radial compression around the circumference of the single septum 130 facilitates its self-sealing. When an infusion needle is inserted into the distal reservoir 151, the fluid infused into the distal reservoir 151 travels through the upper fluid path 173 and into the lumen of the double-lumen catheter 400, which is connected to the upper barb 210 of the double-barbed outlet stem 200. Similarly, when an infusion needle is inserted into the proximal reservoir 157, the fluid infused into the proximal reservoir 157 travels through the lower fluid path 174 and into the lumen of the double-lumen catheter 400, which is connected to the lower barb 220 of the double-barbed outlet stem 200. The arrangement of fluid channels 171, 172, or fluid pathways 173, 174 in the implantable dual-reservoir port 100 provides low resistance to fluid passing through the dual-reservoir access port 100. An implantable dual-reservoir port according to the present invention is particularly suitable for medical applications that may require a high infusion flow rate. A particular example is the automated injection of contrast agent for X-ray computed tomography (CT). In some applications, automated contrast agent injection is required at flow rates up to 5 mL / second. Contrast agents may also have high viscosity, which may require the automated injection equipment to be operated under high back pressure, making it challenging to achieve a high injection flow rate. High pressure increases the risk of failure in conventional infusion systems. Rupture of an implanted port or infusion catheter and separation of the catheter from the port can occur. Small, tortuous internal fluid passages, such as those found within a conventional dual-reservoir implantable port, exacerbate this difficulty. The dual-reservoir access port 100 of the present invention provides straight fluid channels 171, 172 and fluid pathways 173, 174 for both the distal and proximal reservoirs 151, 157. These fluid channels 171, 172 and fluid pathways 173, 174 are free of twists and turns. The fluid channels 171, 172 or fluid pathways 173, 174 of the dual-reservoir implantable port 100 according to the present invention are also entirely of relatively constant shape and cross-sectional size.This also facilitates the passage of low-resistance fluid through the fluid channels or pathways. Designing a conventional dual-reservoir access port to have a fluid channel arranged in a side wall increases the port's width or, alternatively, its height. Increasing either the width or height is undesirable because it requires a larger incision and can lead to patient discomfort. The dual port 100 of the present invention minimizes the width because the lower fluid channel 172 is not arranged in the wall 152. It also minimizes the height because the puncture cover 140 and its variations allow for a minimal distance between the bottom 153 of the distal reservoir 151 and the lower fluid channel 172. The reduction in height and width allows for a smaller incision size. In addition, the conventional dual-reservoir access port with the fluid channel located in the side wall presents other problems. Typically, an open-top fluid channel formed in the side wall around the distal reservoir is used in such designs. This open-top channel requires a seal to prevent fluid communication with the distal reservoir. Furthermore, this open-top fluid channel has a large dead zone where the channel width transitions to the proximal reservoir and the port stem. Such dead zones hinder proper port flushing. Particularly when the proximal reservoir is used for blood collection, ineffective flushing of the fluid channel from the side wall can result in an increased risk of clot formation within the fluid channel and compromise the access port's function. With reference to Figure 6, a front view of the outlet stem 200 portion of the double-reservoir access port 100 is illustrated, according to an exemplary embodiment of the present invention. As can be seen in Figure 6, the upper prong 210 has a rounded locking projection 212 arranged around its outer surface. The lower prong 220 also has a rounded locking projection 222 arranged around its outer surface. The rounded locking projection 212 of the upper prong 210 and the rounded locking projection 222 of the lower prong 220 are not aligned; that is, the rounded locking projections 212 and 222 are not located at the same distance from the distal end 216 and 226 of the upper and lower prongs 210 and 220 of the double-prong outlet stem 200.In this particular example, the rounded locking lug 212 of the upper prong 210 is located proximally, i.e., closer to the base of the stem 230 compared to the rounded locking lug 222. The rounded locking lug 222 of the lower prong 220 is located closer to the distal end of the lower prong 220 than the locking lug 212. The rounded locking lug 222 is located at a first distance from the distal end of the lower prong 220, and the rounded locking lug 212 is located at a second distance from the distal end of the upper prong 210 that is greater than the first distance. The locking lugs 212 and 222 have semicircular cross-sections. Figure 7A is another example front view of the double-pronged outlet stem 200 portion of the double-reservoir access port 100 of line GG illustrated in Figure 6, according to an example embodiment of the present invention. Figure 7C is an example cross-sectional view of the double-pronged outlet stem 200 of the double-reservoir access port 100 taken along sectional line II shown in Figure 7A, according to an example embodiment of the present invention. As illustrated in Figure 7A, each of the upper and lower prongs 210 and 220 of the double-pronged outlet stem 200 is generally semicircular in shape. With reference now to Figures 7A and 7C together, the upper and lower pin locking projections 210 220 are illustrated in more detail. Specifically, the locking lug of the upper prong 210 includes the rounded locking lug 212 polished in Figure 6 (also referred to herein as the outer curved locking lug) located on the curved outer surface of the upper prong 210 and an additional locking lug 214 (a straight inner locking lug) located on the flat side of the prong 210 facing the prong 220. Similarly, the locking lug of the lower prong 220 includes the rounded locking lug 222 polished in Figure 6 (also referred to herein as the outer curved locking lug) located on the curved outer surface of the lower prong 220 and an additional locking lug 224 (a straight inner locking lug) located on the flat side of the prong 220 facing the prong 210. It can be seen how the locking lugs 212 and 214 for both the upper prong 210 of the double-pronged outlet stem 200 and the locking lugs 222 and 224 of the lower prong 220 surround the outer circumference of the respective prong 210 and 220. The outer curved locking lug 212 of the upper prong 210 follows the outer curved contour of the outside of the upper prong 210, and the straight inner locking lug 214 of the upper prong 210 follows the generally flat side of the upper prong 210 facing the lower prong 220. The outer curved locking lug 222 of the lower prong 220 follows the outer curved contour of the outside of the lower prong 220, and the straight inner locking lug 224 of the lower prong 220 follows the generally flat side of the lower prong 220 facing the upper prong 210.In this view, the locking projections 212 214 of the upper prong 210 are not aligned with respect to the locking projections 222 224 of the lower prong 220 and are closer to the base of the stem 230. The curved and flat external surfaces of the stems define the fluid channels within the prongs 210 220. In this particular embodiment, the upper and lower prongs 210 220 are slightly tapered on their curved outer sides and also on the flat sides where they meet. Due to the slight taper of the upper and lower prongs 210 220, the locking lugs 212 214 of the upper prong 210 have a slightly greater circumferential length than the locking lugs 222 224 of the lower prong 220. Specifically, the arc length of the locking lug 212 is greater than the arc length of the locking lug 222, and the length of the locking lug 214 is greater than the length of the locking lug 224. The upper and lower fluid channels 171 and 172 are generally of constant size along all their respective prongs 210 220. With reference now to Figure 7B, a cross-sectional view of the double-pronged outlet stem 230 taken along the sectional line HH illustrated in Figure 6 is shown. As shown in Figure 7B, the upper fluid channel 171 and the lower fluid channel 172 comprise the semicircular cross-sections 171.2 and 172.2 respectively at the base 230. In this embodiment, the upper fluid channel 171 is stacked vertically on top of the lower fluid channel 172. Figure 8 illustrates an example view of a cross-section of the double-lumen catheter 400 taken along the sectional line BB illustrated in Figure 2, according to an example embodiment of the present invention. The double-lumen catheter 400 comprises an outer wall 480 surrounding two lumens 440 and 450, which are separated from each other by a dividing wall 470. The outer wall 480 of the double-lumen catheter 400 is generally of a circular or oval cross-section. The lumens 440 and 450 are generally D-shaped or C-shaped, although other shapes may be used. The lumens 440 and 450 may be the same size. The internal dimensions of the lumens 440 and 450 are comparable to the external dimensions of the upper and lower barbs 210 and 220 of the double-barbed outlet stem 200. Figure 9A is an example side cross-sectional view of an embodiment where a double-lumen catheter 400 and a locking collar 300 are positioned for connection to the double-barbed outlet stem 200 of the double-reservoir access port 100, according to an example embodiment of the present invention. The locking collar 300 comprises two generally hollow, cylindrical end sections 310 and a narrow middle portion 320. The two end sections 310 are identical; that is, the locking collar 300 is symmetrical about a midpoint of the middle portion 320. The locking collar 300 can therefore be used in either direction. The symmetrical shape greatly simplifies the connection of the double-lumen catheter 400 to the double-reservoir port 100, as a clinician does not need to distinguish the orientation of the locking collar 300 during the implantation procedure. The narrow middle section 320 of the 300 locking collar has a larger internal diameter IVIA / a / ZUZZ / UI 40^1 smaller than the end sections 310. In the embodiment shown in Figure 9A, the inside of both end sections 310 tapers gradually towards the inside diameter of the narrow middle portion 320. The inside diameter of the narrow middle portion 320 is slightly larger than the combined outside diameter of the upper and lower prongs 210 220 between the offset locking lugs 212 214 of the upper prong 210 and the locking lugs 222 224 of the lower prong 220. The width of the narrow middle portion 320 is approximately equal to or slightly shorter than the offset distance between the locking lugs 212 214 of the upper prong 210 and the locking lugs 222 224 of the lower prong 220. The narrow middle portion 320 is designed to fit between the rounded locking lug of the upper barb 212 and the rounded locking lug of the lower barb 222 in their locked position, thereby frictionally securing the double-lumen catheter 400 to the double-barbed outlet stem 200. When a clinician connects the double-lumen catheter 400 to the dual-reservoir access port 100, they first slide each lumen 440 and 450 of the double-lumen catheter 400 over the upper barb 210 and the lower barb 220 of the double-barbed outlet stem 200, respectively, and push the double-lumen catheter 400 onto the locking lugs 212 and 214 of the upper barb 210 and the locking lugs 222 and 224 of the lower barb 220. The cone incorporated into the upper and lower barbs 210 and 220 This facilitates the operation. The doctor then slides the locking collar 300 over the pair of locking protrusions 222 224.The locking collar 300 is in the locked position when the locking collar 300 rests between the locking lugs 212 214 and the locking lugs 222 224. In the particular embodiment shown in Figure 9A, the maximum distance between the lugs (measured from the midpoint of the locking lugs 212 214 of the upper prong 210 to the midpoint of the locking lugs 222 224 of the lower prong 220) is approximately 0.32512 centimeters, and the internal width of the narrow middle portion 320 (including the ramps on either side of the midpoint of the locking collar 300) is also approximately 0.32512 centimeters. Figure 9B illustrates a side cross-sectional view of the double-lumen catheter 400 and a locking collar 300 attached to the stem 200 of the dual-reservoir access port 100, according to an exemplary embodiment of the present invention. When the locking collar 300 is in the locked position, the upper and lower outer locking projections 212 and 222 compress the outer wall 480 of the double-lumen catheter 400 against the inside of the locking collar 300, particularly against the narrow middle portion 320. The upper and lower inner locking projections 214 and 224 compress the dividing wall 470 of the double-lumen catheter 400 against the opposite prong. In other words, the inner locking projection 214 compresses the dividing wall 470 against the prong 220, and the inner locking projection 224 compresses the dividing wall 470 against the prong. 210. These multiple compression points contribute to the creation of a fluid-tight connection between the 400 double lumen catheter and the 100 dual reservoir access port. In the embodiments shown in Figures 6, 7, and 9, the locking lugs 212, 214 of the upper prong 210 are located closer to the base of the stem 230, and the locking lugs 222, 224 of the lower prong 220 are located closer to the distal end 216, 226 of the double-pronged outlet stem 200. This configuration of locking lugs is for illustrative purposes only and does not limit the scope of the present invention. It should be understood that the relative positions of the locking lugs of the upper prong and the locking lugs of the lower prong can be reversed and placed anywhere along the double-pronged outlet stem. Figure 10A is a cross-sectional view of a modality of an individual septum 130 used with an example modality of the double-reservoir access port 100 of the present invention. The individual septum 130 comprises an upper dome 131, an upper compression zone 139, a flange 133, and a lower plug 137. The flange 133 comprises a flat upper surface 135 and a flat lower surface 136. In this particular embodiment, the flange 133 further comprises an upper sealing ring 132, a side sealing ring 134, and a lower sealing ring 138. The upper and lower sealing rings 132 and 138 are rounded projections located respectively on the upper and lower surfaces 135 and 136 of the flange 133. The side sealing ring 134 is a thin strip surrounding the outer circumference of the flange 133. In the embodiment illustrated in Figure 10A, the side sealing ring has a rectangular cross-section.It is envisaged that septa with other shapes and configurations can be used with the present implantable port with double reservoir of the invention, provided that fluid-tight seals can be formed over the distal and proximal reservoirs. Figure 10B is an enlarged cross-sectional view of portion J of Figure 4A, illustrating a portion of the septum 130 assembled in the cap 110 and the port base 150 of an embodiment of the dual-reservoir access port 100, according to an exemplary embodiment of the present invention. When the cap 110 is locked in place against the port base 150, the cap 110 compresses the single septum 130 against the port base 150. The upper sealing ring 132 and the side sealing ring 134 of the septum 130 are in contact with the cap 110 and deform to form fluid-tight seals. The lower sealing ring 138 is in contact with the upper surface 154 of the port base 150 and deforms to form a fluid-tight seal.The lower plug 137 is also radially compressed against the side walls 152 158 of the respective distal and proximal reservoirs 151 157, providing additional assistance in sealing the respective reservoirs. With reference now to Figure 11A, an exemplary perspective view of an alternative embodiment of the puncture cover 140, generally designated as 1100, according to an exemplary embodiment of the present invention, is illustrated. The puncture cover 1100 comprises a pair of end portions 1120A and 1120B. The end portion 1120A comprises a lumen 1130A having a D-shaped cross-section 1160A, and the end portion 1120B comprises a lumen 1130B having a D-shaped cross-section 1160B. The flat-side portions of the D-shaped portions 1120A and 1120B are uniformly connected to each other by a flat portion 1110. Viewed another way, the puncture cover 1100 is a D-shaped tube from which a semicircular portion is removed to leave the flat portion 1110 and the end portions 1120A and 1120B. With reference now to Figure 11B, an example cross-sectional view of an example embodiment of the double port 100, generally designated as 100', is illustrated, in which the piercing cover 140 is replaced with the piercing cover 1100, according to an example embodiment of the present invention. It should be understood that the similar elements in Figures 1 to 3 and 5 are illustrated in Figure 11B. The view in Figure 11B is of a cross-section of the port 100' taken along a sectional line similar to sectional line AA illustrated in Figure 2. Figure 11B illustrates that the puncture cover 1100 is disposed in portion 164D of the base 150 below the bottom 153 of the distal reservoir 151 to prevent a needle 500 from penetrating the bottom of the reservoir 151 and accessing the lower fluid channel 172. The puncture cover 1100 is also disposed between the bottom 153 of the distal fluid reservoir 151 and the second fluid path 174. At least a portion 1144A of the puncture cover 1100 (corresponding to portion 144A of the puncture cover 140) is disposed within portion 164A of the lower fluid channel 172 directly below the distal reservoir 151. It is understood that the puncture cover 1100 may extend through the lower fluid channel 172 beyond the walls 152 of the distal fluid reservoir 151, such as through portion 164D illustrated in Figures 5B-5C. It is also understood that the puncture cover 1100 may be of other sizes and shapes, such as C-shaped, stadium-shaped, oval, triangular, rectangular, or trapezoidal, to match lumens 172.1 and 172.3 if they are C-shaped, stadium-shaped, oval, triangular, rectangular, or trapezoidal. The puncture cover 1100 is formed from a material that is harder than the material forming the base of the port 150. More preferably, the material is one that, at a thin thickness, would withstand penetration by an infusion needle. In one example modality, the puncture cover 1100 is a metal or metal alloy tube that lines at least portion 164C of the lower fluid channel 172 directly below the distal reservoir 151. In one example modality, titanium is used for the construction of the puncture cover 1100. An example wall thickness for such a tubular titanium puncture cover is approximately 0.127 centimeters. Other metals or metal alloys, for example, stainless steel, may also be suitable for constructing the puncture cover. With respect to Figures 11A and 11B together, the flat portion 1110 of the puncture cover 1110 comprises a width 1150 that is desirably greater than the width of the fluid channel 172 to ensure that the fluid channel 172 is fully covered to prevent a needle from penetrating through the bottom of the reservoir 151 and into the fluid channel 172. The puncture cover 140 comprises a length 1140 that is desirably greater than the length of portion 164C of the fluid channel 172. At least three embodiments are contemplated for the puncture cover 1100 lining the lower fluid channel 172. In one embodiment, portion 164D of the lower fluid channel 172 in which the puncture cover 1100 is disposed, is notched so that the inner lumen 1130A 1130B of the puncture cover 1100 in the end portions 1120A and 1120B have the same cross sections 1160A and 1160B as the cross section 172.4 of the inner lumen 172.3 of the lower fluid channel 172 in portion 164E. The fluid channel 172 outside portion 164D and the lumen 1130A and 1130B of the puncture cover 1100 together form the second lower fluid path 174 comprising a lumen 174.1 with a cross section 174.2. In this embodiment, the cross section 174.2 of the effective fluid path 174 is the same at all points between the distal tip 226 and the opening 228, except in the portion between the end portions 1120A and 1120B because the lower portion of the notched portion 164D is not completely filled by a corresponding portion of the puncture cover 1100. In another embodiment, the notched portion 164D of the lower fluid channel 172 has the same shape as the puncture cover 1100. Therefore, the cross-section 174.2 of the effective fluid path 174 is the same at all points between the distal tip 226 and the opening 228 and is equal to the cross-section 172.4. In yet another embodiment, the lower fluid channel 172 is not notched. Therefore, the cross-section 172.2 is equal to the cross-section 172.4 in portion 164E. The cross-section of the lower fluid channel 172 is constant along all lengths of the lower fluid channel 172 from the distal tip 226 to the opening 228. The puncture cover 140 fits into the lower fluid channel 172. Therefore, the lumen 174.1 of the effective fluid path 174 has a slightly narrower cross-section 174.2 where the puncture cover 1100 is disposed in the lower fluid channel 172. With reference now to Figure 12A, an example front view of an alternative embodiment of the stem 200, generally designated as 200', according to an example embodiment of the present invention, is illustrated. As can be seen in Figure 12A, the upper prong 210 of the stem 200' comprises a first rounded locking projection 1210A and a second locking projection 1210B arranged around its outer surface. The lower prong 220 comprises a first rounded locking projection 1220A and a second rounded locking projection 1210B arranged around its outer surface. The flat inner surfaces 1212 and 1222 of the respective prongs 210 and 220 are smooth and do not contain locking projections. With reference now to Figure 12B, a flat front view of the stem 200' of a line KK illustrated in Figure 12A is shown, according to an exemplary embodiment of the present invention. Figure 12C illustrates an exemplary cross-sectional view of the double-pronged outlet stem 200' taken along a sectional line LL illustrated in Figure 12B, according to an exemplary embodiment of the present invention. As illustrated in Figure 12B, each of the upper and lower prongs 210 and 220 of the double-pronged outlet stem 200' is generally semicircular in shape, as is the case with the double-pronged outlet stem 200. Figures 12B and 12C together illustrate the locking projections 1210 and 1220 of the upper and lower prongs 210 and 220 in more detail. Specifically, locking lugs 1210A and 1210B are each an external curved locking lug located on the curved external surface of the upper prong 210. Similarly, locking lugs 1220A and 1220B are each an external curved locking lug located on the curved external surface of the lower prong 220. Neither locking lug 1210A nor 1210B includes an internal straight locking lug located on the flat internal surface 1212 of the prong 210 facing the prong 220, and neither locking lug 1220A nor 1220B includes an internal straight locking lug located on the flat internal surface 1222 of the prong 220. Each of the locking lugs 1210A and 1210B has a semicircular cross-section as illustrated in Figure 12C. Specifically, locking lug 1210A has a semicircular cross-section 1211A and locking lug 1210B has a semicircular cross-section 1211B. Similarly, each of the locking lugs 1220A and 1220B has a semicircular cross-section. Specifically, locking lug 1220A has a semicircular cross-section 1221A and locking lug 1220B has a semicircular cross-section 1221B. The semicircular cross-sections 1211 and 1221 of the locking protrusions 1210 and 1220 facilitate the insertion of the catheter 400 into the stem 200', since the catheter 400 passes over the rounded surfaces more easily than if the surfaces were spike-shaped.At the same time, locking lugs 1210 and 1220 allow the use of the locking collar 300 to secure the catheter 400 to the dual port 100. When slid over the catheter 400 disposed on the stem 200', the narrow middle portion 320 of the locking collar 300 is positioned between locking lugs 1210A and 1210B and between locking lugs 1220A and 1220B. The locking lugs 1210 of the upper prong 210 of the double-pronged outlet stem 200' and the locking lugs 1220 of the lower prong 220 do not encircle the outer circumference of the respective prongs 210 and 220, unlike the locking lugs 212 and 222, as described above. The curved outer locking lugs 1210 of the upper prong 210 follow the curved contour of the outside of the upper prong 210. As mentioned above, there is no corresponding straight inner locking lug on the flat inner surface 1212 of the upper prong 210. The curved outer locking lugs 1220 of the lower prong 220 follow the curved contour of the outside of the lower prong 220. As mentioned above, there is no corresponding straight inner locking lug on the flat inner surface 1222 of the lower prong 220. In the particular embodiment illustrated in Figures 12A-C, the upper and lower prongs 210 and 220 are slightly tapered on their curved outer surfaces and also on the flat surfaces 1212 and 1222 by which they meet. Due to the slight taper of the upper and lower prongs 210 and 220, the locking projection 1210B of the upper prong 210 has a slightly longer arc length than the locking projection 1210A, and the locking projection 1220B of the lower prong 220 has a slightly longer arc length than the locking projection 1220A. The upper and lower fluid channels 171 and 172 are generally of constant, i.e., transverse, size along the entire length of the stem 200' despite their taper. The tapered shape of the barbs 210 and 220 of the stem 200' facilitates the insertion of the catheter 400 into the stem 200'. The constant cross-sectional size of the fluid channels 171 and 172 facilitates the appropriate flow characteristic during infusion. The double-barbed outlet stem 200 and 200' and the port base 150 can be manufactured as a single piece or as separate pieces by molding or other suitable manufacturing techniques. If manufactured as separate pieces, the double-barbed outlet stem 200 or 200' and the port base 150 can be joined by welding, solvent welding, bonding, or other suitable manufacturing methods. To manufacture the port base 150 by injection molding, a mold is formed, and mandrels for the fluid channels 171 and 172 are inserted into the mold. The puncture cover 140 or 1100 is positioned around the mandrel for the lower fluid channel 172. The material forming the port base is then injected into the mold. The base of port 150 is removed from the mold and mandrels, and the septa 130 are pressed against the reservoirs 151 and 157. The separately molded cap 110 is fitted onto the base of port 150.Preferably, the cap 110 is solvent-bonded to the base of the port 150. The dual-reservoir access port 100 or 100' is complete. Alternatively, the base of the port 150, the outlet stem 200 or 200', and the cap 110 can be integrally formed, for example, injection-molded using a removable bolt or machined from a single material. ML / a / ZUZZ / UI 40^1 in stock. In one example embodiment, the dual-reservoir access port 100 or 100' is formed from biocompatible plastic materials. The cap 110 and the port base 150 can be made from polysulfone resin or acetal plastic. The cap 110 and the port base 150 can be made from the same material or from different materials. Additional suitable plastic materials, not limited to, include polyvinyl chloride, polytetrafluoroethylene, polyethersulfone, polyethylene, polyurethane, polyetherimide, polycarbonate, polyetheretherketone, polysulfone, polypropylene, and other compounds known to the art. Each individual septum 130 is typically made from a silicone elastomer, such as polysiloxanes and other similar compounds known to the art. In one example modality, the 400 double lumen catheter is formed from a biocompatible plastic or elastomer, preferably from a biocompatible elastomer.Suitable biocompatible plastics include materials such as, for example, polysiloxanes, silicone, polyurethane, polyethylene, vinyl acetate homopolymers and copolymers such as ethylene vinyl acetate copolymer, polyvinyl chlorides, acrylate homopolymers and copolymers such as polymethyl methacrylate, polyethylene methacrylate, polymethacrylate, ethylene glycol dimethacrylate, ethylene dimethacrylate and hydroxymethyl methacrylate, polyurethanes, polyvinylpyrrolidone, 2-pyrrolidone, polyacrylonitrile butadiene, polycarbonates, polyamides, fluoropolymers such as polytetrafluoroethylene and polyvinyl fluoride homopolymers and copolymers, polystyrenes, styrene acrylonitrile homopolymers and copolymers, cellulose acetate, acrylonitrile butadiene styrene homopolymers and copolymers, polymethylpentene, polysulfones, polyesters, polyimides, polyisobutylene, polymethylstyrene and other similar compounds known to those skilled in the art.It should be understood that these potential biocompatible polymers are included above for illustrative purposes and should not be interpreted as limiting. Preferably, the 400 double-lumen catheter is formed from the elastomeric material so that it is flexible, durable, soft, and can easily conform to the shape of the catheterization area in a patient, minimizing the risk of damage to the blood vessel walls. The 400 double-lumen catheter is preferably formed from a soft silicone or polyurethane elastomer having a hardness of approximately 80-A on the Shore durometer scale. This elastomer may include radiopaque materials, such as 20% barium sulfate, to provide radiopacity. In the particular embodiment shown in Figures 1 and 3, a cavity 501 is formed in the dividing wall 155 of the base of port 150 between reservoirs 151 and 157. The cavity 501 is of a size that can accommodate an identification device, preferably a chip of IVIA / a / ZUZZ / UI 403Ί Radio frequency identification (RFID), such as a micro RFID device manufactured by PositiveID Corporation. The identification device is preferably hermetically sealed and stores information about the implantable port. In one example embodiment, an RFID chip is installed in cavity 501, which provides a device serial number, date, and batch information and identifies port 100 as a dual-reservoir access port 100 suitable for high-pressure injections. Other information may also be encoded within the identification device. It should be understood that the location of cavity 501 may be anywhere within the implantable port, provided it does not interfere with the port's functionality. These and other advantages of the present invention will be evident to those skilled in the art from the preceding description. Consequently, those skilled in the art will recognize that changes or modifications can be made to the described embodiments without departing from the broad inventive concepts of the invention. Therefore, it should be understood that this invention is not limited to the particular embodiments described herein, but rather is intended to include all changes and modifications that fall within the spirit and scope of the invention.

Claims

1. A double-barbed outlet stem, comprising: a first barb having a proximal end, a distal end, and a first distal tip having a first distal opening; a second barb having a proximal end, a distal end, and a second distal tip having a second distal opening; wherein: the double-barbed outlet stem can be attached to an access port base having a first reservoir and a second reservoir, wherein the first distal opening is in fluid communication with the first reservoir of the access port base and the second distal opening is in fluid communication with the second reservoir of the access port;the first barb comprises a first locking projection disposed on an outer surface of the first barb, the second barb comprises a second locking projection disposed on an outer surface of the second barb, the first locking projection is offset from the second locking projection by an offset distance such that the first locking projection is at or near the proximal end of the first barb and the second locking projection is at or near the distal end of the second barb, wherein a double-lumen catheter can be secured to the double-barbed outlet stem by means of a locking collar having a narrow middle portion, the narrow middle portion having a width approximately equal to or slightly shorter than the offset distance; the first barb has a length that is equal to the length of the second barb;The first prong has a semicircular cross-section and the second prong has a semicircular cross-section, wherein: the first prong has a first flat surface and a first curved surface which together form a first outer circumference of the prong, the first locking projection projects from the first prong and completely surrounds the first outer circumference of the prong; the second prong has a second flat surface and a second curved surface which together form a second outer circumference of the prong, the second locking projection projects from the second prong and completely surrounds the second outer circumference of the prong; each of the first locking projection and the second locking projection are rounded; and the first flat surface and the second flat surface face each other.

2. The double-barbed outlet stem according to claim 1, wherein the first distal opening provides a first fluid path having a constant cross-section 30, and the second distal opening provides a second fluid path having a constant cross-section.

3. The double-pronged outlet stem according to claim 1, wherein at least one of the first locking projections and the second locking projections has a semicircular cross-section.

4. The double-pronged outlet stem according to claim 1, wherein the first curved surface and the first flat surface of the first prong exhibit a decrease towards the first distal tip and the second curved surface and the second flat surface of the second prong exhibit a decrease towards the second distal tip.

5. A double-pronged outlet stem for use with an access port, comprising: a first prong having a proximal end and a distal end; a second prong having a proximal end and a distal end; a symmetrical locking collar comprising a first hollow section, a second hollow section and a narrow middle portion between them, wherein the symmetrical locking collar can be positioned on the double-pronged outlet stem in any direction;wherein the double-barbed outlet stem is designed to receive a double-lumen catheter, and the locking collar secures the double-lumen catheter to the double-barbed outlet stem, wherein the first barb comprises a first locking projection disposed on an outer surface of the first barb, the second barb comprises a second locking projection disposed on an outer surface of the second barb, the first locking projection is offset from the second locking projection by an offset distance such that the first locking projection is at or near the proximal end of the first barb and the second locking projection is at or near the distal end of the second barb, wherein the narrow middle portion of the symmetrical locking collar is positioned within the offset distance when the double-lumen catheter is secured to the double-barbed outlet stem;wherein the first prong has a length equal to the length of the second prong; wherein the first prong has a semicircular cross-section and the second prong has a semicircular cross-section, wherein: the first prong has a first flat surface and a first curved surface which together form an outer circumference of the first prong, the first locking projection extends from the first prong and completely surrounds the outer circumference of the first prong; the second prong has a second flat surface and a second curved surface which together form an outer circumference of the second prong, the second locking projection extends from the second prong and completely surrounds the outer circumference of the second prong; IVIA / a / ZUZZ / UI 40^1 each of the first locking projection and the second locking projection are rounded; and the first flat surface and the second flat surface face each other.

6. The stem referred to in claim 5, wherein a first distal opening provides a first fluid path having a constant cross-section, and a second distal opening provides a second fluid path having a constant cross-section.

7. The stem referred to in claim 5, wherein the first hollow section is cylindrical and the second hollow section is cylindrical.

8. The stem referred to in claim 5, wherein the locking collar is symmetrical about a midpoint of the narrow middle portion, wherein the first hollow section and the second hollow section have identical outside and inside dimensions, wherein the narrow middle portion is symmetrical about the midpoint.

9. The stem referred to in claim 8, wherein, in a locked configuration, the narrow middle portion of the symmetrical locking collar is located between the first locking projection and the second locking projection, and the first hollow section and the second hollow section of the symmetrical locking collar enclose the first locking projection and the second locking projection.

10. The stem referred to in claim 5, wherein the narrow middle portion has a middle portion internal diameter, the first hollow section has a first section internal diameter, and the second hollow section has a second section internal diameter, and the first section internal diameter at one end of the first hollow section and the second section internal diameter at one end of the second hollow section are each larger than the middle portion internal diameter.

11. The stem referred to in claim 10, wherein the diameter of the first section tapers gradually from the end of the first hollow section to the narrow middle portion to match the inner diameter of the middle portion, and the inner diameter of the second section tapers gradually from the end of the second hollow section to the narrow section of the middle portion to match the inner diameter of the middle portion.

12. An access port base, comprising: a proximal end having a proximal fluid reservoir; a distal end having a distal fluid reservoir, a first fluid path in fluid communication with the distal fluid reservoir; a second fluid path in fluid communication with the proximal fluid reservoir; and a double-barbed outlet stem projecting from the distal end, the double-barbed outlet stem comprising: a first barb having a proximal end and a distal end, the first barb comprising a first distal tip having a first distal opening, wherein the first distal opening is in fluid communication with the first fluid path;a second barb having a proximal end and a distal end, the second barb comprising a second distal tip having a second distal opening, wherein the second distal opening is in fluid communication with the second fluid path; wherein the first barb comprises a first locking projection disposed on an outer surface of the first barb, the second barb comprises a second locking projection disposed on an outer surface of the second barb, the first locking projection being offset from the second locking projection by an offset distance such that a double-lumen catheter can be secured to the double-barbed outlet stem via a locking collar having a narrow middle portion, the narrow middle portion having a width approximately equal to or slightly shorter than the offset distance;wherein the first locking projection is on or near the proximal end of the first prong and the second locking projection is on or near the distal end of the second prong; wherein the first prong has a length equal to the length of the second prong; wherein the first prong has a semicircular cross-section and the second prong has a semicircular cross-section, wherein: the first prong has a first flat surface and a first curved surface which together form an outer circumference of the first prong, the first locking projection extends from the first prong and completely surrounds the outer circumference of the first prong; the second prong has a second flat surface and a second curved surface which together form an outer circumference of the second prong, the second locking projection extends from the second prong and completely surrounds the outer circumference of the second prong;Each of the first locking projections and the second locking projections are rounded; and the first flat surface and the second flat surface face each other.

13. The access port base referred to in claim 12, wherein the distal fluid reservoir, the proximal fluid reservoir, and the double-pronged outlet stem are arranged in line with each other.

14. The access port base referred to in claim 12, wherein the first spike, the second spike, the first fluid path, and the second fluid path are stacked with at least one horizontal and one vertical offset from each other.

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