Abstract:
A fluid manifold that consistently and reliably delivers fluids to one or more subject interfaces is provided. A branched pattern of bifurcated lumina carrying the fluid from a source to the outlets in each subject interface provides substantially equal amounts of fluid to each subject interface, thereby reducing the risk of over- or under-delivery of the fluid. A fluid-scavenging system is also included. A plurality of exhaust inlets in the interior of the subject interfaces is connected to a source of negative pressure through a channel and exhaust port to collect fluid before it can escape the subject interface, thereby reducing the risk of escaping fluid reaching the atmosphere.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of the filing date of U.S. provisional patent application Ser. No. 61/867,405, attorney docket number UND 14-008, filed on Aug. 19, 2013, entitled “Anesthesia Manifold for Equal Delivery and Scavenging of Isoflurane to Mice and Rats,” the disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    There are many fields where there is a need for the delivery of a fluid or vapor to an animal. Two important applications are in veterinary procedures, and research settings. Often in research, for example, it would be beneficial to sedate multiple laboratory animals at once; this is especially true in the field of preclinical optical imaging where a control cohort is compared to an experimental cohort. This multiple animal sedation is currently achieved in a number of ways, most commonly focusing on the delivery of the gaseous anesthetic to the nose or mouth of the lab animals through a bulky deployment chamber and individual nose-cones. A pump forces an anesthetic from a source to the inlet of a manifold. The inlet leads to a chamber with several outlets which can be fitted with external nose-cones. The laboratory animals are positioned with their noses propped in these cones so that as they breathe, they inhale the anesthetic gas. 
         [0003]    The fluid or vapors inevitably escape from the nose-cones, and leak into the atmosphere, which poses health concerns for those working with these systems and the environment. Currently, several methods exist for reducing or eliminating the escape of gases from these apparatuses. One method involves completely enclosing the laboratory animals in an air-tight chamber attached to a vacuum line and gas trap; but this design requires more space, is more traumatic for the animals, and can limit the techniques which can be used to image the enclosed animal. A second method involves scavenging fluid after it has escaped the subject interface, such as by positioning inlets exterior to the outermost lip of the nose-cones. These inlets are routed to a vacuum line and gas trap and thus scavenge a portion of the excess gas that has diffused outside the subject interface. 
       BRIEF SUMMARY 
       [0004]    The following presents a simplified summary in order to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview. It is not intended to either identify key or critical elements or to delineate the scope of the claimed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later. 
         [0005]    In embodiments, a fluid delivery device for providing a fluid to at least one subject, comprises a receiving port that directs said fluid into said body member, at least three subject interfaces, each having at least one outlet for discharging the fluid, and a plurality of successively bifurcated lumina connecting said receiving port to said outlets wherein the plurality of lumina are substantially equal in dimensions. In embodiments, said bifurcated lumina rejoin via at least one reconnection point. 
         [0006]    In another embodiment, a fluid delivery device for providing a fluid to a subject comprises a body member that comprises a receiving port for directing fluid into said body member, a lumen connected to said receiving port, a subject interface, wherein said subject interface is a cavity within the body member for receiving at least a portion of said subject and exposing said subject to the fluid, and wherein said lumen carries the fluid from said receiving port to said subject interface, at least one exhaust inlet for collecting the fluid from said subject interface, wherein said at least one exhaust inlet is disposed within said subject interface, a channel connected to said at least one exhaust inlet; and an exhaust port for removing fluid wherein said exhaust port is attached to said body member and said channel carries the fluid from said at least one exhaust inlet to said exhaust port. In embodiment, the fluid delivery device comprises a diffuser interposed between said lumen and said subject interface. 
         [0007]    The fluid delivery device comprises a body member with one or more subject interfaces. Each subject interface has an outlet and exhaust inlets in the interior of the subject interface. The body member has a base; the base is sufficiently flat for abutting a planar work surface. The base of the body member has a cavity for affixedly receiving a magnet. The body member has a slot between adjacent subject interfaces which can removably receive and retain a divider. The divider is a plate with a thickness equal to the width of the slot. 
         [0008]    A receiving port on the body member directs a fluid into the body member, and a plurality of successively bifurcated lumina connects the receiving port to the outlets in the subject interfaces. The segments after each bifurcation are equally-dimensioned. In embodiments, adjacent segments of adjacent bifurcations join into a single segment. An exhaust port on the body member is in fluid communication with the exhaust inlets via a channel in the body member. 
         [0009]    To accomplish the foregoing and related ends, certain illustrative aspects of the claimed subject matter are described herein in connection with the following description and the annexed drawings. These aspects are indicative of various ways in which the subject matter may be practiced, all of which are intended to be within the scope of the claimed subject matter. Other advantages and novel features may become apparent from the following detailed description when considered in conjunction with the drawings. 
     
    
     
       A BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The systems, devices and methods may be better understood by referring to the following description in conjunction with the accompanying drawings, in which like numerals indicate like structural elements and features in various figures. The components in the figures are not necessarily to scale, and simply illustrate the principles of the systems, devices and methods. The accompanying drawings illustrate only possible embodiments of the systems, devices and methods and are therefore not to be considered limiting in scope. 
           [0011]      FIG. 1   a  shows a perspective view of an embodiment of a manifold with five subject interfaces. 
           [0012]      FIG. 1   b  shows an alternate perspective view of the same embodiment of  FIG. 1   a.    
           [0013]      FIG. 1   c  shows a bottom view of the same embodiment of  FIG. 1   a.    
           [0014]      FIG. 2   a  shows an exploded view of another embodiment of a manifold with five subject interfaces. 
           [0015]      FIG. 2   b  shows a cross-section view of a cut-away along plane I of the embodiment of  FIG. 2   a.    
           [0016]      FIG. 2   c  shows an orthogonal view of the embodiment of  FIG. 2   a.    
           [0017]      FIG. 2   d  shows a perspective view of the embodiment of  FIG. 2   a.    
           [0018]      FIG. 3   a  shows a schematic representation of a bifurcated pattern of lumina for embodiments of a manifold with an even number of subject interfaces. 
           [0019]      FIG. 3   b  shows a schematic representation of a bifurcated and rejoining pattern of lumina for an embodiment of a manifold with an odd number of subject interfaces. 
           [0020]      FIG. 3   c  shows a perspective view of an arrangement of lumina in an embodiment of a manifold with five subject interfaces. 
           [0021]      FIG. 3   d  shows an alternate perspective view of an arrangement of lumina shown in  FIG. 3   c.    
           [0022]      FIG. 4  shows an alternate perspective of the core shown in  FIG. 2   a.    
           [0023]      FIG. 5  shows a top view of the interior of the shell of the embodiment of  FIG. 2   a.    
           [0024]      FIG. 6   a  shows a perspective view of an arrangement of lumina in an embodiment of a manifold with five subject interfaces. 
           [0025]      FIG. 6   b  shows an alternate perspective view of an arrangement of lumina in an embodiment of a manifold with five subject interfaces. 
           [0026]      FIG. 6   c  shows a perspective view of an arrangement of sub-channels in an embodiment of a manifold with five subject interfaces. 
           [0027]      FIG. 6   d  shows an alternate perspective view of an arrangement of sub-channels in an embodiment of a manifold with five subject interfaces. 
           [0028]      FIG. 6   e  shows a perspective view of an arrangement of lumina and sub-channels in an embodiment of a manifold with five subject interfaces. 
           [0029]      FIG. 6   f  shows a perspective of an embodiment of the core. 
           [0030]      FIG. 7  shows a bottom view of an embodiment of a manifold with four subject interfaces on each side of the body member. 
           [0031]      FIG. 8  shows a perspective view of an embodiment of a manifold with one subject interface with a triangular body member. 
           [0032]      FIG. 9  shows a perspective view of an embodiment of a manifold with three subject interfaces and removable dividers. 
           [0033]      FIG. 10  shows a perspective view of an embodiment of a manifold with a baffle in the outlet. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    Aspects of the system and methods are described below with reference to illustrative embodiments. The references to illustrative embodiments below are not made to limit the scope of the claimed subject matter. Instead, illustrative embodiments are used to aid in the description of various aspects of the systems and methods. The description, made by way of example and reference to illustrative reference is not meant to being limiting as regards any aspect of the claimed subject matter. 
         [0035]    Embodiments of the manifolds described herein can be used in conjunction with existing sources of fluids and negative pressure to evenly distribute a fluid, or mixture of fluids, to one or more subjects. As used herein, “fluid” refers to a gas, vapor, liquid, or aerosol. In currently available fluid delivery systems, the fluid is urged into a single chamber with outlets or through a trunk and branch arrangement. 
         [0036]    These arrangements lead to uneven delivery of the fluid to the different outlets, as each outlet is a different distance from the inlet. When anesthetizing multiple animals, uneven doses of anesthesia can lead to over-sedation or under-sedation of the animals, potentially harming the animal or allowing the animal to waken during imaging and disrupting procedures. Embodiments of the manifold described herein improve distribution of the fluid, such that the animals receive equal or substantially equal amounts of fluid. 
         [0037]    In addition, the manifolds described herein can reduce or minimize the escape of excess fluid from the subject interfaces. Escaping fluids can pose health concerns for the animal subjects as well as the human operators. The described manifolds can scavenge the fluid before it leaves the subject interface, thereby reducing the risk of harm to both humans and animal subjects. 
         [0038]    In most optical imaging instruments, the amount of functional space is limited; therefore, any obstructions of this space are undesirable. The use of nosecones can increase the amount of functional space taken up by the delivery system. The embodiments of the manifolds described herein utilize a compact and noseconeless design to reduce the bulk and increase the amount of functional space of the imaging instrument that can be utilized. 
         [0039]    Referring now to  FIG. 1   a,  generally, the described manifolds  100  are comprised of a body member  102 , a receiving port  106  for directing fluid into the manifold  100 , lumina  300  connecting the receiving port  106  to outlets  108  in the subject interfaces  104 , exhaust inlets  114  for collecting excess fluid, and a channel  206  connecting the exhaust inlets  114  to an exhaust port  110 . 
         [0040]    The receiving port  106  can be connected to a source of fluid directly through a hose, through a hose adapter, or other suitable means. Fluid is directed in through the receiving port  106  and into the lumina  300 , shown in detail in  FIG. 3   a - 3   d  below. The fluid travels through the lumina  300  and is delivered to the subject interfaces  104  through outlets  108  in the interior of the subject interfaces  104 . Once the fluid has been delivered to the subject interface  104 , it can be inhaled by a subject, for example, a laboratory rat or other animal. The amount of fluid or mixture of fluids can be carefully controlled by external means, including but not limited to, an anesthesia delivery system, a simple valve, or flow regulator. 
         [0041]    Located on the interior of the subject interface  104  is at least one exhaust inlet  114  connected to the channel  206 . The channel  206  is in fluid communication with the exhaust port  110 , which is capable of connecting to a source of negative pressure such as through a hose, or hose adapter. When a negative pressure is applied to the exhaust port  110 , fluid is drawn in from the subject interface  104  through the inlets and channel  206  and out of the body member  102 . This drawing of fluid through the exhaust inlets  114  will minimize or prevent the fluid from escaping the subject interfaces  104 . During operation, if there are fewer subjects than subject interfaces  104 , the need to block off unused subject interfaces  104  is eliminated, which is advantageous because blocking an interface would alter the flow to the remaining subject interfaces  104 . 
         [0042]    In embodiments, the subject interfaces  104  are cavities in the body member  102 , sized to receive the nose of the intended subject animal. In the illustrated embodiment, the subject interface  104  intersects the base  112  and an adjacent face of the body member  102 , creating an aperture to receive the nose of the subject animal. The work surface on which the body member  102  is placed forms a bottom to the cavity. This design allows the manifold  100  to be placed over, or removed from subject animals without disturbing their position. The cavity design of the subject interface  104  can reduce the amount of functional space of the imaging instrument that is taken up by the manifold  100 . Additionally, since the subject interface  104  is a cavity rather than a separate cone, material costs can be reduced. 
         [0043]      FIGS. 1   a - c  illustrate an embodiment of a manifold  100  with five subject interfaces  104  in the body member  102 .  FIG. 1   a  provides a perspective top view of the manifold  100 . In the illustrated embodiment, the receiving port  106  is located on top of the body member  102  for ease of access. As one skilled in the art will appreciate, the position of the exhaust port  110  can be located on various surfaces of the body member  102  as may be required and/or desired in certain embodiments. Within the body member  102 , a series of lumina  300  (explained further in the discussion of  FIGS. 3   a - d ) deliver the fluid to the outlets  108  (seen in  FIG. 1   b ) in the subject interfaces  104 . 
         [0044]    Turning to  FIG. 1   b,  a perspective bottom view of the same embodiment of a manifold  100  illustrates a possible location for the outlets  108  within the subject interfaces  104 . In this illustrative embodiment, three exhaust inlets  114  are spaced approximately evenly at the interior edge of the subject interfaces  104 . The base  112  of the body member  102  is substantially flat so that when resting on a flat work surface (e.g. an imaging bed) the base  112  forms a seal with the work surface against fluids escaping under the manifold  100 . 
         [0045]    Turning to  FIG. 1   c,  a bottom view of the same embodiment of a manifold  100  shows the exhaust inlets  114  are located adjacent to the perimeter of the subject interface  104  on the interior surface within a recessed arch. This position captures or scavenges the fluid prior to escape from the subject interface  102  and before dissipation into the atmosphere. As will be understood by one skilled in the art, the size, arrangement and number of exhaust inlets  114  can be modified from what is described herein as may be required and/or desired in certain embodiments. The exhaust inlet  114  is an aperture through the body member  102  to a channel  206  (explained further in the discussion of  FIG. 2   b ) formed in the interior of the body member  102  in fluid communication with the exhaust port  110 . Returning to  FIG. 1   a,  in the illustrated embodiment, the exhaust port  110  is located opposite the base  112  for ease of access. As one skilled in the art will appreciate, the position of the exhaust port  110  can be located on various surfaces of the body member  102  as may be required and/or desired in certain embodiments. 
         [0046]    In certain embodiments, the body member  102  can be of a monolithic, solid, construction as with 3D printing or other methods. 
         [0047]    Referring to  FIG. 2   a , in embodiments, the body member  102  can be made of multiple parts fitted together. As illustrated, the body member  102  comprises a lid  200 , a core  202 , and a shell  204 . Production in multiple parts can save production costs by allowing more traditional methods of manufacture, such as injection molding; and allow a wider range of usable materials. Suitable materials for the construction of the manifolds  100  include, but are not limited to, chemically resistant plastics such as polyamides, polypropylene, polyethylene, and acrylics. Different materials may be used for different intended applications. For example, a common anesthetic is isoflurane, which degrades ABS and PLA plastics; accordingly the manifold  100  can be made either in part or entirely of an acrylic or other chemically resistant material to resist chemical deterioration. 
         [0048]    In an embodiment, the core  202  fits into the shell  204  and is held in the correct vertical alignment by tapers on the front and back of the core  202  and the inner walls of the shell  204 , and a mating surface of the outlet  108 . A mating cavity  400 , illustrated in  FIG. 4 , in the lower surface of the core  202  accommodates an O-ring to enhance the seal between the core  202  and the shell  204 . The lid  200  can be affixed to the shell  204  with adhesive such as epoxy, or other suitable means including, but not limited to, plastic welding. 
         [0049]      FIG. 2   b  shows a cross-sectional view along I of the shell  204  of  FIG. 2   a . The core  202  is shown in phantom seated in the shell  204 , and the lid  200  is shown in phantom seated above the core  202 . In the illustrated embodiment, the channel  206  is formed by the interior space of the shell  204  below the core  202 . As one skilled in the art will appreciate, the channel  206  can be arranged in other configurations as may be required and/or desired in certain embodiments. When a negative pressure is applied to the exhaust port  110 , fluid is drawn in from the subject interface  104  through the exhaust inlets  114  and channel  206  and out of the body member  102 . In embodiments, the exhaust port  108  comprises apertures in the lid  200  and core  202  in fluid communication with the channel  206 . 
         [0050]    In embodiments, a diffuser  208  is disposed about the outlet  108  to aid in the mixing and dispersal of fluid within the subject interface  104 . In certain embodiments, the diffuser  208  comprises an inner wall  210  and an outer wall  212 , where each of the walls  210 ,  212  has a slit or aperture that allows the fluid to pass from the outlet  108  to the subject interface  104 . Depending on the flow rate of the fluid at the outlet  108 , the diffuser  208  can improve the efficiency of fluid scavenging. In the illustrated embodiment in  FIGS. 2   b - d,  the inner wall  210  surrounds the outlet  108  on both the horizontal and vertical planes, leaving clearance below the horizontal plane. The inner wall  210  can be shaped to direct the flow of the fluid; for example, as shown in  FIG. 2   b , the inner wall  210  includes an angled slit that directs fluid flow vertically, rather than directing the flow directly out of the subject interface  104 . In the illustrated embodiment, the outer wall  212  surrounds the inner wall. As one skilled in the art will appreciate, other diffuser configurations can be used as may be desired and/or required in certain embodiments. As shown, the slits or apertures in the walls  210 ,  212  can be offset to disperse the fluid within the subject interface  104 . Dispersion reduces the potential for fluid to be propelled from the outlet  108  directly out of the subject interface  104  and increases the ability of the exhaust inlets  114  to scavenge the fluid. 
         [0051]    As shown schematically in  FIGS. 3   a  and  3   b , in embodiments, the lumina  300  are successively bifurcated until the desired number of subject interfaces  104  is reached. In embodiments, each lumen  300  is substantially the same in diameter, and the path length from the receiving port  106  to each of the subject interfaces  104  is substantially identical. Therefore, the resulting distribution of fluid is substantially equal between each subject interface  104 . As shown, a bifurcation  302  can be implemented with a T-junction or any other configuration that facilitates even flow between both segments of the lumina  300  after the bifurcation  302 . This even flow facilitates consistent delivery of fluid to the subject interfaces  104  and subject animals, reducing or eliminating problems of over and under delivery seen with other manifolds. Additionally, the even flow allows adjustment of the flow to every subject interface  104  simultaneously by adjusting the flow of the source. 
         [0052]    For embodiments with an even number of subject interfaces  104 , as shown in  FIG. 3   a , the lumina  300  are successively bifurcated until the desired number of subject interfaces  104  is reached. 
         [0053]    For embodiments with an odd number of subject interfaces  104  greater than one, as shown in  FIG. 3   b , the lumina  300  are successively bifurcated and rejoined at bifurcation  302  and reconnection joints  304  until the desired number of subject interfaces  104  is reached. The reconnection joints  304  allow generally equal distribution of the fluid for an odd number of subject interfaces  104 . For example, as shown in  FIG. 3   a , after the initial bifurcation  302 , each segment of the lumina  300  splits in two secondary bifurcations  302  and four secondary segments. In contrast in  FIG. 3   b , at the reconnection joint  304  two of these secondary segments are rejoined to become a single secondary segment, ultimately resulting in three secondary sections. This pattern of bifurcation and rejoining of branches between closest hierarchal relative branches continues until the desired number of outputs  106 , corresponding to the number of subject interfaces  104 , is reached. The rejoined reconnection joints  304  are illustrated as T-junctions, but any configuration that facilitates the anastomosis of two lumina  300  would be suitable. 
         [0054]    Fluid dynamics calculations were performed for a five subject interface model using Autodesk Simulation CFD 2015 with a flow rate of 2 L/min for gas input and 0 psi of internal pressure. The turbulence model used was k-epsilon. This yielded an equal flow rate and volume of 20% of the original at each of the five outlets. 
         [0055]      FIGS. 3   c  and  3   d , show an illustrative arrangement of the lumina  300 . For clarity, in these figures, only the walls of the lumina  300 , the receiving port  106 , and the mating cavity  400  are shown. In embodiments, the lumina  300  can be formed by any suitable means such as from tubing, or integrated into the body member  102  as voids as the manifold  100  is formed, for example, by 3D printing. 
         [0056]    As shown, fluid would enter the receiving port  106 , flow through the lumina  300  to the approximate center of the body member  102  and then successively bifurcate and rejoin through the bifurcation  302  and reconnection points  304  until it exits a mating cavity  400 , shown in  FIG. 4 , to transfer to the shell  204 , and then to the subject interfaces  104  through the outlets  108 . 
         [0057]    Turning to  FIG. 4 , in embodiments where the body member  102  of the manifold  100  is comprised of multiple parts, the core  202  includes the mating cavity  400  in the lower surface of the core  202  for accommodating an O-ring to enhance the seal between the core  202  and the shell  204 . 
         [0058]      FIG. 5  shows a top view of an embodiment that utilizes magnets  500  to secure the body member  102  to a magnetic work surface or plate  504 . In certain embodiments, magnets  500  can be incorporated in or near the base  112  of the body member  102 . As one skilled in the art will understand, the magnets  500  may be installed in many ways as may be required and/or desired in certain embodiments. For example, in embodiments where the body member  102  is composed of multiple pieces, the magnets  500  can be affixed to the interior of the body member  102  by adhesive or physical hold-downs  502 , as shown in  FIG. 5 . Magnets  500  can improve the seal between the base  112  of the body member  102  and a magnet compatible work surface or plate  504  by holding tight to the surface via magnetism. As used herein, “magnet compatible” refers to material capable of adhering to a permanent magnet, such as a paramagnetic or a ferromagnetic material. A tighter seal minimizes the escape of fluid from the subject interface  104  by reducing potential for fluid to leak between the support surface and the base  112  of the body member  102 . Stronger magnets, such as rare earth magnets, can result in stronger magnetic attractions. 
         [0059]    A transfer plate or plate  504 , at least a portion of which is magnet compatible, can be useful when a magnet compatible work surface is not available (e.g. epoxy resin laboratory bench tops). Additionally, the plate  504  can be utilized to more easily prepare subject animals prior to insertion into an imaging apparatus. Once arranged, the plate  504 , subject animals, and manifold  100  can be carried and inserted into the imaging apparatus. 
         [0060]    Turning now to  FIGS. 6   a - b,  an alternate arrangement of the lumina  300  is shown. Such an arrangement can allow for a more complex channel  206  arrangement, described below. For clarity, in these figures, only the walls of the lumina  300 , the receiving port  108 , and the mating cavity  400  are shown. 
         [0061]    Turning now to  FIGS. 6   c - d,  in an embodiment, the channel  206  comprises multiple sub-channels  600  through the core  202  that successively converge and diverge to eventually result in a single channel  206  in fluid communication with the exhaust port  110 . The channel  206  is organized analogously to the lumina  300  to achieve a consistent draw from the exhaust inlets  114 . In contrast to the lumina  300 , the channel  206  moves the scavenged fluid from multiple exhaust inlets  114  to a single exhaust port  110 . However, the even draw from the exhaust ports  114  pulls the fluid through the channel resulting in substantially even removal of the fluid from the subject interfaces  104 . For clarity, in these figures, only the walls of the channel  206 , the sub-channels  600 , and the exhaust port  106  are shown. 
         [0062]      FIG. 6   e  shows the lumina  300  and channel  206  of the same embodiments of  FIGS. 6   a - d  packed together. For clarity, in this figure, only the walls of the lumina  300 , the channel  206 , the receiving port  106 , exhaust port  106 , and the mating cavity  400  are shown. 
         [0063]    In embodiments, the receiving port  106  and the exhaust port  110  are threaded for receiving a threaded adapter. 
         [0064]      FIG. 6   f  illustrates an embodiment of a core  202  including a channel  206  comprised of sub-channels  600  that provide an even draw from the exhaust ports  114 . 
         [0065]    Turning now to  FIGS. 7 and 8 , as will be appreciated by one having ordinary skill in the art, the size, number, and arrangement of subject interfaces  104  can be changed as is required and/or desired in certain embodiments. For example,  FIG. 7  shows an embodiment that incorporates subject interfaces  104  on multiple sides of the body member  102 . As shown, two opposite sides each have four subject interfaces  104 . In another example,  FIG. 8  shows an embodiment with one subject interface  104  in a triangular body member  102 . Such an embodiment may be well-suited for placement in a corner. While depicted examples are generally rectangular or triangular, it will be appreciated that any suitable shape can be utilized, including but not limited to, curved, domed, or angled shapes. 
         [0066]      FIG. 9  shows an embodiment wherein the body member  102  includes slots  900  located between adjacent subject interfaces  104 . The slots  900  are capable of removably retaining dividers  902 . In embodiments, the dividers  902  have at least a portion with complimentary shape and thickness to the slot  900  to allow a force fit between the divider  902  and body member  102 . Dividers  902  provide physical barriers between specimens as may be desirable to prevent inter-specimen contact. As one skilled in the art will appreciate, the dividers  902  can be composed of materials either transparent or opaque to the imaging technique. Transparent materials can provide a physical barrier without interfering with imaging. Opaque materials can reduce the influence of potential inter-specimen light contamination. The removable design of the dividers  902  allows for efficient storage and easier cleaning. 
         [0067]    Turning to  FIG. 10 , the outlet  108  can include a baffle  1000  to disperse the flow of fluid from the outlet  108 . In the illustrated embodiment, the baffle  1000  is shown as a cross, but any suitable shape can be used. In embodiments, a baffle  1000  can be present alone, or in conjunction with a diffuser  208 . 
         [0068]    As an illustrative example, in operation in conjunction with an imaging apparatus, the subjects are first sedated in an induction chamber or by another method. Once sufficiently conditioned, the subjects are transferred to an imaging platform. Hose adapters connected to a source of fluid and a source of negative pressure are connected to the receiving port  106  and exhaust port  108 , respectively and the fluid and negative pressure are adjusted as necessary. The fluid delivery manifold  100  can then be installed by aligning the subject interfaces  104  over the subjects&#39; noses and placing the manifold  100  on the imaging platform. 
         [0069]    In use, the flow rate of the vacuum is typically adjusted to be about ten-fold greater than the flow rate of the fluid delivery at the outlet  108 . In lower fluid flow rate procedures, the flow rate of the vacuum is about five-fold greater than the flow rate of the fluid delivery at the outlet  108 . In higher fluid flow rate procedures, the flow rate of the vacuum is about 15 to 20-fold greater than the flow rate of the fluid delivery at the outlet  108 . 
         [0070]    The rate of flow at each subject interface  104  is controlled simultaneously by adjusting the flow upstream from the fluid delivery manifold  100 . Such adjustment can be accomplished by various means including, but not limited to, an anesthesia delivery system, a valve, or a flow regulator. When the number of subject interfaces exceeds the number of subjects, it is not necessary to block off the unused subject interfaces  104 , because the negative pressure will draw any delivered fluid from the empty subject interfaces  104  regardless of the presence of a subject. This allows a desired flow rate to be maintained without having to adjust for the number of subjects present for a particular procedure. 
         [0071]    What has been described above includes examples of aspects of the claimed subject matter. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the claimed subject matter, but one of ordinary skill in the art may recognize that many further combinations and permutations of the disclosed subject matter are possible. Accordingly, the disclosed subject matter is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the terms “includes,” “has” or “having” or variations in form thereof are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.