Abstract:
A tilting apparatus for supporting and restraining a non-human primate animal while conducting research. The tilting apparatus is provided with a table for supporting the animal reclining face down thereon. The table is supported by support means for rotation about a first axis between a horizontal position and a head-down position and about a second axis between the head-down position and a head-up position. Locking means are provided for releasably locking the table in a selected horizontal, head-down or head-up positions. Suitable restraining means are provided which are intersecurable between the animal and the table and function to support and restrain the animal. The animal, while remaining restrained to the tilting apparatus, has free range of motion to feed itself from a water and feeding station. The water and feeding station is supported by an accessory pole. A waste collection system is provided which is connected to the table and which functions for collecting animal waste. A biosensor protective shield is supported by the accessory pole and prevents the animal from accessing chronically-implanted biosensors and instrumentation.

Description:
This application claims benefits from the filing of provisional application No. 60/023,483 filed on Aug. 15, 1996. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to a tilting apparatus and, in a preferred embodiment thereof, more particularly provides a uniquely constructed and operative tilt table for use in animal research studies involving non-human primates, such as rhesus monkeys. 
     The use of head-down tilt as a ground-based surrogate to determine physiological effects of microgravity is well known in scientific literature. (Bloomqvist C G, Stone H L. Cardiovascular Responses to Gravitational Stress. In: Shepherd J T, Abboud F M. eds. Handbook of Physiology: The Cardiovascular System. Bethesda: Am. Physiol. Soc. 1983: 1025-63, Sect. 2, Vol. 3, Chapt. 28; Kakurin L L, Lobachik V I, Mikhailov V M, Senkevich Yu A. Antiorthostatic Hypokinesia as a Method of Weightlessness Simulation, Aviat. Space Environ. Med., 47:1083-6). It is known to have tables or chairs for restraining research subjects during such tilt studies. 
     U.S. Pat. No. 4,890,579 to Oloff, describes an apparatus for rotating immobilized non-human primate animal test subjects about one or more axes to simulate weightlessness during micro-gravity research studies. The apparatus includes a frame, a subframe rotatably attached to the frame and a carrier for a primate restraint system rotatably attached to the subframe. Two motors, controlled by a programmable controller, individually rotate the subframe and the carrier according to a preselected sequence. Animal test subjects are immobilized by means of a primate restraint system, such as that described in U.S. Pat. No. 4,120,266 to Oloff, et al. The Oloff, et al. restraint system uses a combination of clamps and straps to secure the test animal to padded supports. Unfortunately, the Oloff, et al. restraint system limits the test animal&#39;s range of motion, impairs the animal&#39;s ability to maintain its natural habits, and may result in physiological stressors to the animal, such as adrenergic responses, which may detrimentally impact test results. During long-term studies, the animal must be sedated. Moreover, the animal is subject to muscle atrophy and bed sores during long-term studies. In addition, because of its complex, mechanical, motor-driven design, the Oloff rotating apparatus is difficult to use and expensive to manufacture. 
     It is therefore a principal object of the present invention to provide a tilting apparatus for adequately supporting and restraining a non-human primate animal during tilt studies such that the animal, while remaining restrained to the tilting apparatus, has a free range of motion of its head and limbs so that the animal may feed itself and so that the animal is at reduced risk for bed sores, muscle atrophy and physiological stressors during long-term studies. 
     It is a further object of the invention to provide a simple, static tilt table design. 
     A feature of the present invention is that it provides means for the animal to feed itself and waste collection means. 
     A further feature of the present invention is that it provides convenient access to the animal test subject. 
     An advantage of the present invention is that it provides a tilting apparatus which is easily rotatable about horizontal axes and quickly movable between horizontal, head-down tilt and head-up tilt positions. 
     These, and other objects, features and advantages of the present invention will become apparent as the detailed description of a preferred embodiment thereof proceeds. 
     SUMMARY OF THE INVENTION 
     In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, a tilting apparatus is provided which has a table for supporting a non-human primate animal reclining face down thereon. The table is supported by support means for rotation about a first axis between a horizontal position and a head-down position and about a second axis between the head-down position and a head-up position. Locking means are provided for releasably locking the table in selected horizontal, head-down or head-up positions. Suitable restraining means are provided which are intersecurable between the animal and the table and function to support and restrain the animal. The animal, while remaining restrained to the tilting apparatus, has free range of motion to feed itself from a water and feeding station. The water and feeding station is supported by an accessory pole. A waste collection system is provided which is connected to the table and which functions for collecting animal waste. A biosensor protective shield is supported by the accessory pole and prevents the animal from accessing chronically-implanted biosensors and instrumentation. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The present invention will be more clearly understood from a reading of the following detailed description in conjunction with the accompanying drawings wherein: 
     FIG. 1 is a side view of a tilting apparatus which embodies principles of the present invention showing a non-human primate animal restrained face-down thereon in a horizontal position. 
     FIG. 2 is a side view of the tilting apparatus showing the animal restrained facedown thereon in a head-down position. 
     FIG. 3 is a side view of the tilting apparatus showing the animal restrained facedown thereon in a head-up position. 
     FIG. 4a is a perspective view of a table of the invention and FIG. 4b shows a layer of bedding overlying the table of FIG. 4a. 
     FIG. 5a is a perspective view of padding which overlies the table and provides adjustable support for the animal, and FIG. 5b shows the padding positioned on the table. 
     FIG. 6 shows a jacket which is disposed about the body of the animal and secures the animal to the table. 
     FIG. 7a is a perspective view of a protective shield which fits around the front and sides of the animal&#39;s body as positioned on the table; FIG. 7b is a top view of the shield; FIG. 7c is a front view of the shield; FIG. 7d show a side panel for the shield allowing height adjustment according to animal size. 
     FIGS. 8a-e show an exploded view of uptight support members and rear support members, which provide means for supporting the table for rotation about horizontal axes between horizontal, head-down and head-up positions. FIG. 8a is a perspective view of a table of the invention; FIG. 8b is a rear leg support for the FIG. 8a table; FIG. 8c shows a rear leg structure for the FIG. 8a table; FIG. 8d shows an upright support structure for the FIG. 8a table; and FIG. 8e shows another rear leg structure view for the FIG. 8a table. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Illustrated in FIG. 1 is a tilting apparatus 10 which embodies principles of the present invention and, in a unique manner subsequently described, is utilized during research to support and restrain a non-human primate animal test subject in horizontal head-down and head-up positions, as depicted in FIG. 1, FIG. 2, and FIG. 3. As shown in FIG. 1, in the horizontal position, the animal&#39;s head is generally disposed in a horizontal plane. The animal&#39;s head is tilted below the horizontal plane in the head-down position, as illustrated in FIG. 2, and above the horizontal plane in the head-up position, as illustrated in FIG. 3. 
     As shown in FIGS. 1-3, 4a and 4b, the tilting apparatus includes a table 12 for supporting a reclining animal. Table 12 comprises a table top 14 supported by a frame 16. Table top 14 is sized to receive the animal in a face-down, forwardly extending position toward the front end of frame 16. A layer of bedding 22, consisting of a high-grade, closed-cell egg crate type foam, overlies table top 14. Frame 16 consists of upper members 24, central members 26, and lower members 28, which extend around the circumference of table top 14, connecting members 30, which extend between members 24, 26 and 28 to provide further stability and strength, and front legs 17 and rear legs 18. A plurality of spaced-apart holes 32 are cut out of table top 14 and bedding 22. A plurality of adjustable brackets 34 are located on the central members 26 of the frame. Spaced apart holes 32 and brackets 34 provide means for restraining the animal to table 12. An opening 36 is cut out of table top 14 and bedding 22 to provide means for animal waste drainage and access to a waste collection system. 
     As shown in FIG. 1, padding 38 overlying table top 14 and bedding 22 provides adjustable support for the animal and is contoured to correspond with the animal&#39;s body. As best illustrated in FIGS. 5a and 5b, two depressed areas 40 adjacent to the rear section of padding 38 provide support for the animal&#39;s legs, which aids in the animal&#39;s comfort while allowing free movement of the hip joints. Depressed area 44 located in the central portion of padding 38 is contoured to accommodate the animal&#39;s abdomen and chest and to prevent discomfort. The front section of padding 38 is rounded, promoting full range of motion of the animal&#39;s arms and head, enabling the animal to feed itself A waste drainage opening 50 is cut through padding 38 to provide access to a waste collection system. 
     The animal is restrained by means of a jacket 52 illustrated in FIG. 6 which is disposed about the body of the animal. Jacket 52 has arm holes 54 and leg holes 56 through which the arms and legs of the animal can extend. Marginal ends 58 of jacket 52 are secured by means of hook and loop fasteners 60, such as Velcro (TM), so that the jacket 52 fits snugly around the animal&#39;s body. Ties 62 are spaced apart from one another around marginal ends 58 of jacket 52. Ties 62 have inner ends 64 securely affixed to jacket 52 and free ends 66 spaced from jacket 52. The animal is restrained by passing ties 62 through spaced apart holes 32 illustrated in FIG. 4b and securing ties 62 to adjustable brackets 34 illustrated in FIG. 1. In addition to supporting the animal, jacket 52 also provides some warmth and comfort. 
     As illustrated in FIG. 1, the animal, while remaining restrained to table 12, has free range of motion to feed itself from a water and feeding station. Food is available on a forage tray 68 which is placed on bedding 22. Water is contained in a water bottle 70 which is attached to an arm 72 that swings from the side to the center of table 12 allowing the animal to drink as desired. Water bottle 70 and arm 72 are supported by table 12 by means of an accessory pole 74. The bottom portion of accessory pole 74 is attached to frame 16 at upper 24, central 26 and lower 28 members. An adjustable set of brackets 78 located in the upper portion of accessory pole 74 provides support for bottle arm 72 and allows height adjustment. The travel distance of arm 72 is limited by an adjustable cable 82, one end of which is attached to arm 72 and the other to accessory pole 74. 
     The animal is prevented from accessing chronically-implanted biosensors and instrumentation in the animal&#39;s body by means of a biosensor protective shield 84 as illustrated in FIGS. 7a-d. The protective shield 84 is shaped to fit around the front and sides of the animal&#39;s body. The protective shield 84 includes cutouts 86 for the head and shoulders of the animal. Protective shield 84 is placed over the animal&#39;s body so that the animal&#39;s head and arms extend in front of protective shield 84 through cutouts 86. A slide panel 88 is attached to the front of protective shield 84 to allow for height adjustment according to animal size and comfort. As illustrated in FIG. 1, the bottom portion of protective shield 84 rests against bedding 22. The top portion of protective shield 84 is attached to a support arm 94. Support arm 94 is attached by a set of brackets 96 to the top of accessory pole 74. 
     As illustrated in FIG. 3, when table 12 is in the head-up position, the animal is given upright support by means of a saddle 100 which is attached to table top 14. Saddle 100 is adapted to supportingly engage the back side of the animal and includes an opening for waste drainage and access to a waste collection system. 
     As illustrated in FIG. 1 and FIG. 2, during horizontal and head-down tilt, animal waste is collected in a waste container tray 112, which can easily be removed and cleaned, and waste output measured. Waste container 112 is supported by frame 16. As illustrated in FIG. 3, during head-up tilt, animal waste is collected in waste container 114 which is attached to the bottom of saddle 100. 
     As illustrated in FIG. 1, tilting apparatus 10 also includes a pair of front support members 116, a pair of upright support members 117, and a pair of rear support members 118. These support members provide means for supporting table 12 for rotation about first horizontal axis 120, shown in FIG. 1, between a horizontal position and a head-down position, and about a second horizontal axis 122, between a head-down position and a head-up position. 
     As shown in FIG. 1, front support members 116 consist of a pair of front leg supports 124 and a pair of front foot pads 126. A front leg support 124 is attached to the lower portion of each of the front legs 17. Front foot pads 126 are pivotally attached to front leg supports 124. 
     Upright support members 117 consist of a pair of upright supports 132 and a pair of upright foot pads 134. As shown in FIG. 8d, upright supports 132 are generally shaped like right triangles. Upright foot pads 134 are pivotally attached to upright supports 132 at first corners 142. An upright support 132 is rotatably attached at a second corner 144 to upper portions of each of the rear legs 18. Upright supports 132 rotate between a retracted positions illustrated in FIG. 2 and FIG. 3, in which upright supports 132 are generally disposed under table top 14, and engaged positions illustrated in FIG. 3, in which side edges 150 extend perpendicular to rear legs 18. 
     As shown in FIG. 1, rear support members 118 consist a pair of rear leg supports 136, a pair of first rear foot pads 138, and a pair of second rear foot pads 140. As shown in FIG. 8b, rear leg supports 136 are generally shaped like right triangles. First rear foot pads 138 are pivotally attached to rear leg supports 136 at first corners 162. Second rear foot pads 140 are pivotally attached to rear leg supports 136 at second corners 164. A rear leg support 136 is rotatably attached to the lower portions of each of the rear legs 18 at 90 degree corners 168. Rear leg supports 136 rotate between a first position illustrated in FIG. 1, in which short side edges 156 depend from rear legs 18, and a second position illustrated in FIG. 2 and FIG. 3 in which long side edges 158 depend from rear legs 18. 
     Rear leg supports 136 are locked in position by means of rear support release pins 172 as illustrated in FIG. 8b. Pins 172 engage holes 176 in lower portions of rear legs 18 through holes 182 in rear leg supports 136 to lock rear leg supports 136 into the first position. Pins 172 engage holes 176 through holes 184 in rear leg supports 136 to lock rear leg supports 136 into the second position. 
     Upright supports 132 are locked in position by means of upright support release pins 174 in a similar manner. Pins 174 engage holes 180 in upper portions of rear legs 18 through holes 188 in upright supports 132 to lock upright supports 132 into the retracted position. Pins 174 engage holes 180 through holes 190 in upright supports 132 to lock upright supports 132 into the engaged position. 
     Rear leg 136 and upright 132 supports have also been machined with slots 194, as illustrated in FIGS. 8b and d. The slot length is predetermined and allows the supports to swing from one position to the other and back again when release pins 172 and 174 are removed. 
     Table 12 is shown locked in the horizontal position in FIG. 1. The animal is restrained on table 12. Upright supports 132 are pinned in the retracted position. Rear leg supports 136 are pinned in the first position. In the horizontal position, front foot pads 126 support the front end of frame 16 upon the floor and first rear foot pads 138 support the rear end of frame 16 upon the floor. 
     Table 12 is shown locked in the head-down position in FIG. 2 Table 12 is quickly and easily tilted from the horizontal to the head-down position by three people. First, rear support release pins 172 are removed. Next, two people stand at the rear of table 12 on opposite sides and lift. The third person rotates rear leg supports 136 down and pins them into the second position. Then table 12 is set back down. In the head-down position, upright supports 132 remain in the retracted position and front leg supports 124 have pivoted on their front foot pads 126. Front foot pads 126 support the front end of frame 16 upon the floor and second rear foot pads 140 support the rear end of frame 16 upon the floor. Returning to the horizontal position is accomplished by reversing this process. 
     Table 12 is shown in the head-up position in FIG. 3. Starting from the horizontal position, table 12 is quickly and easily tilted to the head-up position by three people. First, saddle 100 is attached to table 12 and the animal is restrained to table 12. Next, tension cable 196 is attached between protective shield support arm 94 and a tension bracket 198 attached to table 12. Upright supports release pins 174 are removed and upright supports 132 are rotated to the engaged position and pinned. Rear support release pins 172 are removed. Two people stand at the rear of table 12 on opposite sides and, while lifting, gently rotate rear leg supports 136 to the second position. Next, two people stand at the front of table 12 on opposite sides and one person stands between them. For the purpose of balance and not weight, they all lift together. Once the table is in the head-up position, rear leg supports 136 are pinned in the second position. In the head-up position, upright foot pads 134 support the upper portion of the rear end of frame 16 upon the floor and second rear foot pads 138 support the lower portion of the rear end upon the floor. Returning to the horizontal position is accomplished by reversing the process. 
     The teachings of all patents, journal articles and other references cited herein are incorporated herein by reference. It is understood that modifications to the invention may be made as might occur to one with skill in the field of the invention within the scope of the appended claims. All embodiments contemplated thereunder which achieve the objects of the invention have therefore not been shown in complete detail. Other embodiments may be developed without departing from the spirit of the invention or from the scope of the appended claims.