Abstract:
A fluid reservoir and administration device for delivering a dosage of a medicament to a patient. The device has a base unit attachable to the skin, a reservoir unit attachable to the base unit, and a cap unit attachable to the reservoir unit. The base unit has a latching member, and a needle. The reservoir unit has a fluid filled cavity, a ratcheting element, a threaded member, and a plunger for forcing the fluid through the needle. The cap unit has ratcheting teeth engagable with the ratcheting member, and a threaded post engagable with the threaded member of the reservoir unit. When the cap unit is rotated, the threaded post is advanced toward the plunger which forces a metered dosage of the fluid through the needle and to the patient. The ratcheting member allows the cap unit to rotate in a single direction, thereby preventing a vacuum in the cavity.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Not applicable 
     FEDERALLY SPONSORED RESEARCH 
     Not applicable 
     SEQUENCE LISTING OR PROGRAM 
     Not applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a wearable insulin delivering button. In particular, it is concerned with a wearable, disposable insulin reservoir and administration device for use in connection with delivering a dosage of insulin or medicament to a patient discreetly and efficiently. 
     2. Description of the Prior Art 
     Wearable, disposable insulin reservoir and administration devices are desirable for providing a user or patient an efficient and discreet device for delivering a dose of insulin or other medicament, while allowing for the quick replacement of the device when depleted. 
     Diabetes is a chronic disease that is characterized by the body&#39;s inability to control glucose levels. Left untreated, it causes damage to the circulatory and nervous systems and results in organ failures, amputations, neuropathy, blindness and eventually death. It has been definitively shown that the cost of the complications related to diabetes significantly exceeds the cost of therapy. 
     Tight control over the delivery of insulin in both type I diabetes (usually juvenile onset) and type II diabetes (usually late adult onset), has been shown to improve the quality of life as well as the general health of these patients. Proper control of blood glucose levels through programmed insulin injection or infusion allows a high quality of life and longer life expectancy. 
     Insulin delivery has been dominated by subcutaneous injections of both long acting insulin to cover the basal needs of the patient and by short acting insulin to compensate for meals and snacks. There are two standard systems of daily insulin therap. 
     The first being syringes and insulin pens. These devices are simple to use and are relatively low in cost, but they require a needle stick at each injection, typically multiple times per day. These device must be carried by the user, so thereby putting the burden on the user to carry enough devices to sustain there activities away from home or medical facilities. 
     The second and most recent development is infusion pump therapy, which entails the purchase of an expensive pump that lasts for about three years. External insulin infusion pumps have allowed the continuous infusion of fast acting insulin for the maintenance of the basal needs as well as the compensatory doses (boluses) for meals and snacks. However, they suffer the drawbacks of being large in size, cost, and high complexity. For example, these pumps are electronically controlled and must be programmed to supply the desired amounts of basal and bolus insulin. This prevents many patients from accepting this technology over the standard subcutaneous injections. Additionally, the initial cost of the pump is a high barrier for many patients. 
     Several attempts have been made to provide ambulatory or “wearable” drug infusion devices. This type of wearable device can provide many of the advantages of an infusion pump without its disadvantages. However, many of these known devices cannot provide precise control over the dosage delivery of the drug at a low delivery cost, and are thus not practical with dose-critical drugs such as insulin. 
     While the above-described devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not describe a wearable, disposable insulin reservoir and administration device that allows delivering a dosage of insulin or medicament to a user discreetly and efficiently. 
     Therefore, a need exists for a new and improved wearable, disposable insulin reservoir and administration device that can be used for delivering a dosage of insulin or medicament to a user discreetly and efficiently. In this regard, the present invention substantially fulfills this need. In this respect, the wearable, disposable insulin reservoir and administration device according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of delivering a dosage of insulin or medicament to a user discreetly and efficiently. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing disadvantages inherent in the known types of wearable medicine buttons now present in the prior art, the present invention provides an improved wearable, disposable insulin reservoir and administration device, and overcomes the above-mentioned disadvantages and drawbacks of the prior art. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved wearable, disposable insulin reservoir and administration device and method which has all the advantages of the prior art mentioned heretofore and many novel features that result in a wearable, disposable insulin reservoir and administration device which is not anticipated, rendered obvious, suggested, or even implied by the prior art, either alone or in any combination thereof. 
     To attain this, the present invention essentially comprises a fluid reservoir and administration device for delivering a dosage of a medicament to a patient. The device broadly has a base unit, a reservoir unit attachable to the base unit, and a cap unit attachable to the reservoir unit. The base unit has a main support, at least one latching member, and at least one needle. The reservoir unit has a housing defining a cavity therein filled with a fluid, at least one ratcheting element located on an exterior of the housing, a threaded member, and a plunger moveable received in said cavity. The housing further has a base configured to be releasably secured to the main support of the base unit by the latching member of the base unit. The cap unit has a side wall, a top wall, a defined open bottom configured to receive the reservoir unit therein, a plurality of ratcheting teeth extending interiorly from the side wall, and a threaded post extending interiorly from the top wall toward the open bottom. The ratcheting teeth are configured to engage with the ratcheting member of the reservoir unit respectively. The threaded post is configured to threadably engage with the threaded member of the reservoir unit. The threaded post has a distal end configured to be contact with and move the plunger of the reservoir unit when the cap unit is rotated. The proximal end of the needle is in fluid communication with the fluid in the cavity of the reservoir unit when the reservoir unit is fitted to the base unit. 
     The main support of the base unit further has an adhesive layer, at least one ridge located adjacent a periphery of the main support, and a sheath fixed to the main support and positioned so as to cover a proximal end of the needle. The ridge is configured to guide and retain the base of the reservoir unit in a position on the base unit. 
     There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated. 
     The invention may also include multiple fingers extending angularly away from the top wall of the reservoir unit and toward each other. With each of the fingers having a distal end which terminate before contacted the distal ends of the remaining fingers and which face each other. The distal ends include threads so as to define a threaded opening between the distal ends of the fingers. 
     Even further, the invention may also include a seal in the base of the reservoir unit that is configured to be perforated by the proximal end of the needle when the reservoir unit is fitted to the base unit. 
     There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims attached. 
     Numerous objects, features and advantages of the present invention will be readily apparent to those of ordinary skill in the art upon a reading of the following detailed description of presently preferred, but nonetheless illustrative, embodiments of the present invention when taken in conjunction with the accompanying drawings. In this respect, before explaining the current embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of descriptions and should not be regarded as limiting. 
     As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
     It is therefore an object of the present invention to provide a new and improved wearable, disposable insulin reservoir and administration device that has all of the advantages of the prior art wearable medicine buttons and none of the disadvantages. 
     It is another object of the present invention to provide a new and improved wearable, disposable insulin reservoir and administration device that may be easily and efficiently manufactured and marketed. 
     An even further object of the present invention is to provide a new and improved wearable, disposable insulin reservoir and administration device that has a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such wearable, disposable insulin reservoir and administration device economically available to the buying public. 
     Still another object of the present invention is to provide a new wearable, disposable insulin reservoir and administration device that provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith. 
     Even still another object of the present invention is to provide a wearable, disposable insulin reservoir and administration device for delivering a dosage of insulin or medicament to a user discreetly and efficiently. This allows for the administering of a metered dose of insulin to the patient using a disposable, cost effective and easy to use device that the patient can apply and administer as needed. 
     Most patients with diabetes use more than one type of insulin during a day. The ability of the reservoir unit to be removed form the base unit allows a patient to switch between insulin&#39;s by replacing and switching between different reservoir units containing different insulin&#39;s. The net effect is that for the approximate three day duration of the base unit being in-situ the patient is wearing only one base unit and has only been required to undergo one uncomfortable insertion event. Note that this is possible because most insulin&#39;s are compatible with each other and can be mixed in one syringe or injected into one depot location under skin. Therefore there is not concern for cross-contamination between insulin&#39;s in the base unit. 
     The removability of the reservoir unit from the base unit is particularly useful for young patients with diabetes from whom multiple injections are painful but who are too immature to trust unsupervised with the reservoir unit attached. The parent would do one insertion event every three days then administer each insulin dose by briefly attaching, dialing the dose (rotating the cap unit) and then removing the reservoir unit. In this manner, multiple daily doses can be administered with no injections. This routine would also benefit any adults with diabetes who also suffer needle phobia or cognitive impairments such that they should not be left alone with an attached insulin reservoir. 
     Historical insulin administration devices use 300 unit cartridges. Because frequent switching out of the reservoir unit is easily done with the present invention, as it offers the possibility of small volume (e.g. 100, 200 unit) reservoir units. Small volume reservoir units are correspondingly flat which enable the entire system to be worn very unobtrusively. 
     These together with other objects of the invention, along with the various features of novelty that characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein: 
         FIG. 1  is a perspective view of the preferred embodiment of the wearable, disposable insulin reservoir and administration device constructed in accordance with the principles of the present invention, with the phantom lines depicting environmental structure and forming no part of the claimed invention. 
         FIG. 2  is an exploded perspective view of the wearable, disposable insulin reservoir and administration device of the present invention. 
         FIG. 3  is a top elevational view of the base unit of the wearable, disposable insulin reservoir and administration device of the present invention. 
         FIG. 4  is a cross-section view of the base unit of the wearable, disposable insulin reservoir and administration device of the present invention, taken along line  4 - 4  of  FIG. 3 . 
         FIG. 5  is an enlarged cross-sectional view of the latch of the base unit of the present invention. 
         FIG. 6  is a top elevational view of the reservoir unit of the wearable, disposable insulin reservoir and administration device of the present invention. 
         FIG. 7  is a cross-section view of the reservoir unit of the wearable, disposable insulin reservoir and administration device of the present invention, taken along line  7 - 7  of  FIG. 6 . 
         FIG. 8  is an enlarge cross-section view of a threaded top portion of the reservoir unit of the present invention. 
         FIG. 9  is a bottom elevational view of the cap unit of the wearable, disposable insulin reservoir and administration device of the present invention. 
         FIG. 10  is a cross-section view of the cap unit of the wearable, disposable insulin reservoir and administration device of the present invention, taken along line  10 - 10  of  FIG. 9 . 
         FIG. 11  is a cross-section view of an in use and assembled wearable, disposable insulin reservoir and administration device of the present invention. 
         FIG. 12  is a cross-section view of a depleted wearable, disposable insulin reservoir and administration device of the present invention. 
     
    
    
     The same reference numerals refer to the same parts throughout the various figures. 
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, and particularly to  FIGS. 1-12 , a preferred embodiment of the wearable, disposable insulin reservoir and administration device of the present invention is shown and generally designated by the reference numeral  10 . 
     In  FIGS. 1 and 2 , a new and improved wearable, disposable insulin reservoir and administration device  10  of the present invention for delivering a dosage of insulin or medicament to a user discreetly and efficiently is illustrated and will be described. More particularly, the wearable, disposable insulin reservoir and administration device  10  has a base unit  12  removably attached to the skin  8  of a user or patient, a reservoir unit  56  removably attached to the base unit  12 , and a cap unit  80  threadably engaged with and removably attached to the reservoir unit  56 . 
     The base unit  12  has a main support  14  including one or more latches  30 , one or more guide ridges  50 , and a flexible sheath  26 , as illustrated in  FIG. 3 . The main support  14  has a, but not limited to, generally circular configuration with the latches  30 , and ridges  50  radially located along a periphery thereof. The main support  14 , latches  30 , and ridges  50  are made of, but not limited to, plastics, polyethylene, polystyrene, polyvinyl chloride and polytetrafluoroethylene (PTFE). It can be appreciated that any suitable material that is human safe or medical grade can be used for the main support, latches, ridges and sheath. 
     As best illustrated in  FIG. 4 , the base unit  14  is firmly secured to the skin  8  of the patient by way of an adhesive layer  22  that is temporally protected by a removable peel-away cover  24 . The adhesive layer  22  is located on a side of the main support  14  opposite the sheath  26 , latches  30 , and ridges  50 , and is able to securely and removably attach to the patient&#39;s skin  8 . A needle  16  projects through at least the base unit  14  and the adhesive layer  22  so as to extend out past both sides of the main support  14 . It can be appreciated that the needle  16  can extend out past the side containing the adhesive layer  22  a distance sufficient enough to penetrate in or through the skin  8  and/or into the fatty layer beneath the skin. The needle  16  can be of any gauge required by the patient, and different base units  12  can be used containing different needle  16  lengths and gauges. The needle  16  has an angled distal end  18  in communication with a lumen  20  defined through the needle  16 . The needle  16  is made of, but not limited to, any medical grade or human safe metals, plastics, and alloys. 
     The sheath  26  has a generally dome-like configuration including a flange  28  extending outwardly from a bottom of the dome sheath  26 . The flange  28  is attached to and received in a recess centrally defined in the main support  14  so that the dome sheath  26  covers a proximal end of the needle  16  opposite its distal end  18 . The sheath  26  is flexible and preferably made of, but not limited to, rubber, so that the needle  16  can penetrate through the dome sheath  26  when the dome sheath is pressed down on the proximal end of the needle  16 . The sheath  26  functions as a cover and a basic occlusion device for the needle  16 , and has a thicker upper occluding portion in comparison to its side walls and the flange  28  of the sheath  26 . In a resting position, as best illustrated in  FIG. 4 , the proximal end of the needle  16  is inside the sheath  26  which provides enough resistance to any insulin or physiological fluid trying to move back up the lumen  20  of the needle  16 . When the sheath  26  is depressed, the proximal end of the needle  16  perforates the upper occluding portion to expose the proximal end. The sheath  26  and the proximal end of the needle  16  can be covered by a releasable sheath cap  29 , thereby protecting the sheath  26  from accidental depression or damage, or from injuring the user while transporting, applying or disposing the base unit  12 . Additionally, the needle  16  can include a removably protective sleeve (not shown) or may be covered by the peel-away cover  24 . 
     The latch  30 , as best illustrated in  FIG. 5 , has an angled inner surface  32 , a substantially top planar surface  34 , and a biasing element  36  that connects the latch  30  to the main support  14 . The angled inner surface  32  has a generally downward and inwardly angled surface toward the main support  14  so as to allow the reservoir unit  56  to be securely latched between the latch  30  and the main support  14 . The biasing element  36  provides a securing or snapping force to the reservoir unit  56  by way of biasing the latch  30  in a pivoting motion toward the base  58  of the reservoir unit  56 . The reservoir unit  56  is released from the latch  30  by applying a force to the top surface  34  against the force of the biasing element  36  which pivots the latch  30  away from the base  58  of the reservoir unit  56  thereby allowing the reservoir unit to be removed therefrom. The latch  30 , biasing element  36  and the main support  14  can be integrally formed in a single piece, with the biasing element  36  being a flexible post between the latch  30  and the main support  14 . The flexible post biasing element  36  can have, but not limited to, a curve, arcuate or straight configuration. It can be appreciated that the base unit  12  can include multiple latches  30  radially located opposite each other near the peripheral edges of main support  14 . 
     An alternate embodiment latch  30 ′, as best illustrated in  FIG. 5 , has an angled inner surface  32 , a substantially top planar surface  34 , and a biasing element  44  that provides a biased pivoting force to the latch  30 ′ toward the main support  14 . The biasing element  44  is a spring, such as but not limited to, a coil spring, a leaf spring, or a torsion spring. The angled inner surface  32  has a generally downward and inwardly angled surface toward the main support  14  so as to allow the reservoir unit  56  to be securely latched between the latch  30 ′ and the main support  14 . The main support  14  includes an upwardly extending support  38  defining a notch  40  for receiving a portion of the spring  44 , and the latch  30 ′ defines a notch  42  for receiving an opposite portion of the spring  44 . A shaft or pin  46  extends through the support  38  and its notch  40 , and the latch  30 ′ and its notch  42 , thereby securing the latch  30 ′ to the support  38 . The spring  44  may have a coil section configured to receive the pin  46  therethrough. The spring  44  provides a securing or snapping force to the reservoir unit  56  by way of biasing the latch  30 ′ in a pivoting motion toward the reservoir unit  56 . The reservoir unit  56  is released from the latch  30 ′ by applying a force to the top surface  34  against the force of the spring  44  which pivots the latch  30 ′ away from the reservoir unit  56  thereby allowing the reservoir unit to be removed therefrom. It can be appreciated that the base unit  12  can include multiple latches  30 ′ radially located opposite each other near the peripheral edges of main support  14 . 
     The guide ridges  50  extend up from the peripheral edge of the main support  14  for assisting and guiding the placement of the reservoir unit  56  onto the main support  14 . The guide ridges  50  each have angle edges  52  located at opposite ends thereof, and each have a curved configuration with an inner radius equal to or less than the radius of the main support  14 . It can be appreciated that the base unit  12  can include multiple guide ridges  50  radially located opposite near the peripheral edges of main support  14 . 
     The reservoir unit  56 , as best illustrated in  FIGS. 6 and 7 , has a base  58 , a substantially cylindrical side wall  63  extending up from the base  58 , a top wall  62  extending across the side wall  63 , and fingers  68  angularly extending up from the top wall  62 . The reservoir unit  58  includes a moveable plunger  72  located in an interior chamber formed by the base  58 , side wall  63 , and top wall  62 . The chamber is prefilled with a fluid  78 , such as but not limited to, insulin or medicament. The base  58 , side wall  63 , top wall  62 , and plunger  72  are made of, but not limited to, a medical grade glass or plastic. 
     The base  58  has a generally cylindrical configuration with a diameter larger than the radius of angled inner surface  32  of the latch  30 ,  30 ′, and less than the radius of the biasing element  36  of latch  30  or support  38  of the latch  30 ′ respectively. The base  58  includes a rubber seal  60  centrally located through the base  58 , and one or more notched ramps  67  extending up from the base  58  and formed integrally with the interior of the side wall  63 . The notched ramps  67  feature opposing angled or ramp-like faces with a notch defined between the faces. The rubber seal  60  is adapted to be perforated by the proximal end of the needle  16  when the reservoir unit  56  is inserted onto and received by the base unit  12 , thereby forcing the seal  60  against the sheath  26  and depressing the sheath to expose the proximal end of the needle  16 . The rubber seal  60  does not allow insulin  78  to leak behind thereof, thereby providing a tight fluidic seal between the seal  60  and the needle  16 . 
     The outer surface of the side wall  63  includes one or more ratcheting ledges  64  extending along the height of the side wall  63  parallel with the longitudinal axis of reservoir unit  56 . A spherical element  66  is located adjacent an end of each ratcheting ledge  64  and adjacent the base  58 , so that the spherical element  66  is located between the end of the ratcheting ledge  64  and an upper surface of the base  58 , as best illustrated in  FIG. 7 . The ratcheting ledges  64  include an angled side and a planar side. The ratcheting ledges  64  consist of, but not limited to, a pair of two ledges  64  located on opposite sides of the side wall  63 , with each ledge  64  having their ratcheting face in the same rotations direction, as best illustrated in  FIG. 6 . It can be appreciated that additional ledges  64  can be incorporated around the outer circumference of the side wall  63 . 
       FIG. 8  best illustrates the fingers  68  of the top wall  62  of the reservoir unit  56 . The fingers  68  consisting of multiple angled members of semi-stiff plastic angularly extending up from the top wall  62 . The fingers  68  each have a distal end  70  which terminates before contacting the distal ends of the remaining fingers so as to form an opening or bore inline with the longitudinal axis of the reservoir unit  56  and with the rubber seal  60  of the base  58 . The distal ends  70  of each finger  68  are interiorly threaded, with the threads being substantially perpendicular to the longitudinal axis of the reservoir unit  56 . 
     The plunger  72  includes one or more protrusions  73 , and a recess  74  centrally located and inline with the longitudinal axis of the reservoir unit  56 , the bore defined by the fingers  68 , and the rubber seal  60  of the base  58 . The protrusions  73  extend downward from a bottom of the peripheral edge of the plunger  72 , and have a radius substantially equal to the radius of the notched ramp  67 . The defined notch in the notched ramp  67  is configured to receive one protrusion  73  therein, and the ramp-like faces guide the protrusion  73  into the notch. An O-ring seal or gasket  76  is located along the periphery of the plunger  72  so as to make a fluidic seal between the plunger  72  and the interior of the side wall  63 . The plunger  72  is moveable along the longitudinal axis of the reservoir unit  56  so as to force insulin  78  through the proximal end of the needle  16  exposed through the rubber seal  60  of the base  58  when the reservoir unit  56  is received in the base unit  12 . 
     The cap unit  80 , as best illustrated in  FIGS. 9 and 10 , has a generally cylindrical configuration including a top wall  82 , a cylindrical side wall  84 , multiple ratcheting teeth  86 , and a threaded post  88 . The top wall  82  extends across the side wall  84 , so as to form an opened bottom cylinder defining an interior cavity. The side wall  84  may contain ridges, grooves or grips along a portion thereof for assisting the user in manipulating the cap unit  80 . The cap unit  80  is made of, but not limited to, plastics, polyethylene, polystyrene, polyvinyl chloride, and PTFE. The side wall  84  of the cap unit  80  has a diameter larger than the diameter of the side wall  63  of the reservoir unit  56 , and less than the radius of the latch  30 ,  30 ′ of the base unit  12 . The side wall  84  further has a height larger than the height of the reservoir unit  56 . 
     The ratcheting teeth  86  are located along the interior circumference of a distal end of the side wall  84 , and have a generally square configuration. When the cap unit  80  is rotated in one radial direction, the ratcheting teeth  86  are configured and sized to slide along the angled side of the ratcheting ledges  64 . When the cap unit  80  is rotated in an opposite radial direction, the ratcheting teeth  86  engage or abut against the planar side of the ratcheting ledges  64  of the reservoir unit  56 . Thus the cap unit  80  can only rotate in a single radial direction when the ratcheting teeth  86  are engaged with the ratcheting ledges  64 , since the ratcheting face or angled side of the ledges  64  are angled in one direction, and the planar side prevents the cap unit  80  from rotating in the opposite direction. It can be appreciated that the ratcheting teeth  86  are able to freely rotate in either radial direction when they are adjacent the spherical elements  66  since the spherical elements  66  do not have a planar face or side to abut against the ratcheting teeth  86 . 
     The post  88  extends into the cavity of the cap unit  80  centrally from the top wall  82 , as best illustrated in  FIG. 10 , and has external threads that engage with the internally threaded distal ends  70  of the fingers  68  of the reservoir unit  56 . The post  88  includes a non-threaded portion adjacent the top wall  82 . The post  88  includes a distal end configured to be received in the recess  74  of the plunger  72  of the reservoir unit  56 , thereby applying a force against the plunger  72  to move the plunger when the cap unit  80  is rotated. The non-threaded section of the post  88  has a size and location to allow the distal ends  70  of the fingers  68  to freely rotate in any radial direction when the ratcheting teeth  86  are adjacent the spherical members  66  of the reservoir unit  56 . 
     In use, as best illustrated in  FIGS. 11 and 12 , it can now be understood that the user would peal away the temporary cover  24  of the base unit  12  to expose the adhesive layer  22 . The base unit  12  is then applied to the skin  8  of the user so that the angled distal end  18  of the needle  16  penetrates the skin  8 . The adhesive layer  22  securely adheres the base unit  12  to the skin  8 , so as not to allow accidental movement or removal of the base unit  12 . The cap  29  is then removed to expose the sheath  26 . 
     The reservoir unit  56  is then placed on the base unit  12  so that the base  58  of the reservoir unit  56  is received within guide ridges  50  and snapped and locked into place by the latch  30 ,  30 ′. The peripheral edge of the base  58  contacts the angled surface  32 , and deflects the latch  30 ,  30 ′ so as to allow the base  58  to be received in the space between the latch  30 ,  30 ′ and the base  58 . The biasing element  36 ,  44  of the latch  30 ,  30 ′ provide a securing force toward the base  58  of the reservoir unit  56  thereby retaining the reservoir unit against a top surface of the main support  14  of the base unit  12 , so that the rubber seal  60  depresses the sheath  26  down in the recess of the main support  14 . Depressing the sheath  26  by the reservoir unit  56  exposes the proximal end of the needle  16  through the sheath  26  and the rubber seal  60 . The proximal end of the needle  16  is now in fluid communication with the insulin  78  in the reservoir unit  56 . 
     The cap unit  80  is then placed on the reservoir unit  56  and rotated so that the threaded post  88  is engaged with the threaded ends  70  of the fingers  68 , and that the distal end of the post  88  is received in the recess  74  of the plunger  72  of the reservoir unit  56 . It can be appreciated that the base unit  12 , the reservoir unit  56 , and the cap unit  80  can be assembled and primed prior to application on the patient. 
     It can further be appreciated that the cap unit  80  reduces cost by allowing the cap unit to be reused since it is not in direct contact with the insulin  78 . However, should manufacturing economics be advantageous, the present invention could be simplified to having the cap unit  80  pre-attached to the reservoir unit  56  with no need for later removal, thereby combining the cap unit and the reservoir unit into a single preassemble unit. 
     The user can then rotate cap unit  80  in a single direction so that the ratcheting teeth  86  of the cap unit  80  engage with the ratcheting ledges  64  of the reservoir unit  56 . Each turn of the cap unit  80  advances the plunger  72  toward the base unit  12  a predetermined distance, thereby forcing a predetermined amount or dose of insulin  78  through the needle  16  and to the patient. Since the ratcheting ledges  64  have a single angular ratcheting face, it can then be appreciated that the cap unit  80  can only be rotated in a single direction, thereby preventing the plunger  72  from being retreated back into the reservoir unit  56  and creating a suction force through the needle  16 . Each turn of the cap unit  80  produces a click-like sound from the ratcheting teeth  86  and ledges  64 , thereby giving the user an audible indication of rotation and administration of insulin. 
     It can be appreciated that the dosage amount dispensed through the needle  16  is related to the angle of the threads in the threaded distal end  70  of the fingers  68  and the threaded post  88 . The greater the angle of the threads the greater the dosage amount per rotation of the cap unit  80 . Different cap units  80  with varying thread angles can be used for varying dosages, thereby providing the patient the ability to alter dosing in relation to the patients diabetes type, age, glucose level, or any other factor relating to insulin dosage. Furthermore, the patient can perform multiple rotations of the cap unit  80  to provided multiple metered dosages of insulin  78 . 
     The angled configuration of the fingers  68  prevents the unwanted and accidental advancement of the cap unit  80  by a pushing force against the cap unit  80  in the longitudinal direction, but allows for withdrawal of the cap unit  80  in an opposite direction. 
     When the user rotates the cap unit  80  so that the plunger  72  is at its depleted lower position, the ratcheting teeth  86  are then positioned adjacent the spherical elements  66  of the reservoir unit  56 , the protrusion  73  of the plunger  72  is then received and locked in the notch defined by the notched ramp  67 , and the threaded distal end  70  of the fingers  68  are adjacent the non-threaded portion of the post  88 . In this depleted or lowermost orientation, the plunger  72  is fixed and prevented from further rotation or advancement by the notched ramp  63 , and the cap unit  80  is free to rotate in either direction because the threaded distal end  70  is free to rotate by the non-threaded section of the post  88  and the ratcheting teeth  86  are free to rotated along the spherical elements  66 . 
     Now that the reservoir unit  56  is depleted of insulin  78 , the cap unit  80  can be removed by pulling the cap unit  80  away from the reservoir unit  56  along substantially its longitudinal axis. The cap unit  80  is able to be pulled out because of the angled configuration and the semi-stiff nature of the fingers  68  which bend or flex outwardly by the upward pulling motion of the post  88 , thereby disengaging the threaded distal ends  70  from the threaded post  88 . 
     Once the cap unit  80  is removed, the user can then remove the reservoir unit  56  by depressing the top planar surface  34  of the latch  30 ,  30 ′ against the force of the biasing element  36 ,  44  so that the angled inner surface  32  of the latch  30 ,  30 ′ pivot away from the base  58  of the reservoir unit  56 . Then the reservoir unit  56  can be pulled away from the base unit  12  and discarded or recycled. When the reservoir unit  56  is removed, the sheath  26  will then extend or pop back out over the proximal end of the needle  16  by the resiliency of the rubber sheath  26 . 
     A new reservoir cap  56  can then be attached to the base unit, and the cap unit  80  can be attached to the reservoir unit  56 , or the sheath cap  29  can then be reattached, and the base unit  12  removed from the skin  8  of the patient and discarded or recycled. 
     It can be appreciated that the wearable, disposable insulin reservoir and administration device of the present invention can be modified so as to be used with existing insulin pump insertion sites, such as but not limited to, the Cleo® 90 Infusion Set, Accu-Check Ultraflex™ Set, Medtronic Paradigm Silhouette™, Medtronic Quickset, and Unomedical™ Comfort Set. Where an alternate embodiment base unit can be used as an adaptor to connect the reservoir unit to the infusion set. 
     While a preferred embodiment of the wearable, disposable insulin reservoir and administration device has been described in detail, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. Although delivering a dosage of insulin or medicament to a user discreetly and efficiently have been described, it should be appreciated that the wearable, disposable insulin reservoir and administration device herein described is also suitable for delivering any liquid to a location in metered dosages. 
     Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.