Abstract:
A palm-held device is disclosed for injection of a substance into an organism. The palm-held device has the shape of a computer mouse, and so is very familiar, which helps with ease-of-use and comfort. Like a computer mouse, the device can be moved easily by gently holding and guiding the mouse with the fingers and the palm of the hand. There are many possible button configurations, such as a single button mouse, the button having a large surface at the front top portion of the mouse, and being pressable by any finger. There can also be a two button mouse, such that the left button actuates the injection, and the right button is the “safety” that allows the left button to actuate the injection. The two buttons can be on the top front of the mouse, or can be on the right and left sides of the mouse.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 13/076,405, filed on Mar. 30, 2011, the content of which is incorporated herein by this reference in its entirety. 
         [0002]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/661,596, filed on Jun. 19, 2012, the content of which is incorporated herein by this reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0003]    This Invention generally relates to administration of substances, and particularly to devices for injection of substances into an organism. 
       BACKGROUND OF THE INVENTION 
       [0004]    Current auto-injectors are typically pen-shaped, pre-loaded, impact-activated syringes. These auto-injectors have concealed needles to help overcome the common fear of needles that may inhibit their use in an emergency situation. The most commonly used auto-injector is EpiPen®, which is an auto-injector that is pre-loaded with a standard dose of epinephrine, which reverses anaphylactic reactions commonly induced by food, drug, or insect venom. Such auto-injectors can also be pre-loaded with other medications. For example, some countries have stockpiles of such auto-injectors for their military and their citizens in preparation for chemical warfare, especially to protect against nerve gas. Prior to use of the auto-injector, a safety cap must be removed to allow the needle to penetrate into the thigh. To distinguish between the needle-end and the safety-cap-end of the auto-injector, each end has a different color and shape. 
         [0005]    One known issue regarding EpiPen® type auto-injectors is that their operation is not intuitive to those who are required to use them. Patients and caregivers are given detailed, in-person explanations and demonstrations of the proper use of an EpiPen®. They are also typically shown a training DVD and are even provided with an EpiPen® Trainer for practice. Yet, it has been observed that about 50% of patients and caregivers fail to demonstrate correct use of the auto-injector during follow-up visits. In an emergency situation, such mistakes often render the EpiPen® ineffective. 
         [0006]    Physicians and nurses are often among the caregivers that fail to correctly use the EpiPen®, and this true even in a calm office environment. For example, one common mistake that is observed is holding the auto-injector upside-down, resulting in accidentally injecting the loaded dose of medication into the thumb of the caregiver or the patient. This common mistake is an unintended result of the design of the EpiPen®. Because the EpiPen® resembles a pen or marker, the user anticipates that the end with the safety cap is the needle end of the auto-injector. Counter-intuitively, the end of the EpiPen® with the safety cap is the end that is opposite to the end housing the needle. Consequently, many EpiPen® users fail to perform the required flip of the device so that the user presses on the needle end, thereby injecting the epinephrine into their own thumb. 
         [0007]    Even if it is the patient&#39;s own thumb, there is no absorption of epinephrine from the thumb, and the patient is deprived of the benefit of the epinephrine. Moreover, the Epinephrine severely constricts the arterial supply to the thumb, and may result in local damage. Reportedly, a child&#39;s life was recently lost due to an anaphylactic shock when a parent wasted the only available EpiPen® dose by injecting it into his/her own thumb. 
         [0008]    Another shortcoming of the EpiPen® type auto-injector is that its mode of use can be intimidating if not frightening for some to use. The recommended motion for administering a dose is shown on the label of the EpiPen® as a stabbing motion into the leg, and is described on the EpiPen® device as: “Jab black tip firmly into outer thigh so it ‘clicks’ AND HOLD on thigh approx. 10 secs.” A current version of the EpiPen® has a label that shows a stabbing motion into the leg, and instructs the user to: “Swing and firmly push.” Consequently, many children and adults are reluctant to use the EpiPen® because of the frightening stabbing nature of the recommended mode of administration. 
         [0009]    A further shortcoming the EpiPen® type auto-injector is that there is no indication when the EpiPen® has completed the injection. This can lead to a failure to administer the full dose of medicine. Many patients and caregivers apply the EpiPen® in a fast downward swinging motion, and then incorrectly lift it off the thigh too soon. This can lead to the premature disengaging of the needle of the EpiPen® from the patient before enough time has passed to ensure delivery of a complete dose of epinephrine. 
         [0000]    Finally, the EpiPen® type auto-injector is not convenient to carry. A single EpiPen® measures 6.5″ in length, and 1.25″ in diameter. Routinely, patients who need to carry epinephrine on their person at all times to save their lives are often instructed by a physician to carry two EpiPens® at all times. This is because a patient may need more than one EpiPen® to reverse a severe allergic reaction. However, only 20-30 percent of patients will actually carry two EpiPens® and the inconvenience of the physical dimensions of the EpiPen® can often deter individuals from carrying even a single EpiPen®. 
       SUMMARY OF THE INVENTION 
       [0010]    The palm-activated injectors of the invention are shaped so as to appear friendly and non-threatening, and are adapted so as to encourage a gentle pressing action for triggering the injection mechanism of the palm-activated injector. Moreover, the shape is conducive to proper application, i.e., proper application means placement of the palm-activated injector prior to actuation of the palm-activated injector, with the needle away from the operating hand, so as to ensure injection into the intended injection site, and NOT inadvertent injection into one&#39;s thumb or hand. The shape can be like a computer mouse, or like a bell-shape such as the bell with a button on top, such as found at the front desk of a hotel or a small retail store that is used to summon the clerk or salesperson. 
         [0011]    Further, the shape of the palm-activated injector suggests application in the correct orientation, and consequently, the possibility of shape-induced confusion regarding application orientation is significantly reduced. In addition, the orientation does not need to change at any time during operation of the device. 
         [0012]    The palm-activated injector in the shape of a mouse or a bell is convenient to carry, including carrying in a small pocket, even when containing multiple doses of medication(s). 
         [0013]    In some embodiments, the concealed needles of the palm-activated injector of the invention are automatically injected only after intentionally deactivating a safety mechanism, such as by pressing a button, sliding a button, or by removing a safety pin, which allows activation of a trigger mechanism, thereby initiating injection of a medication. 
         [0014]    In preferred embodiments of the invention, a(the) needle(s) extend out of the injector only during active administration of the medication, and consequently, needle injuries are unlikely to occur. For example, some embodiments of the palm-activated injector of the invention include a self-withdrawing needle that protects the user from accidental needle-stick after injection. Other embodiments include a self-withdrawing syringe, which concomitantly withdraws the needle upon completion of the injection. 
         [0015]    The injectors of the invention have a non-threatening shape that is not reminiscent of known syringes, such as a computer mouse shape, or a bell shape. Further, the shape of the injectors encourages a more gentle approach of the injecting device to the recipient of the injection. By contrast, since many non-health professionals need to inject themselves and/or their dependents, they are often reluctant to perform the injection using known injectors and known syringes, because the stabbing motion of the injection is commonly perceived to be aggressive and/or threatening by both the caregiver and by the recipient. 
         [0016]    Some embodiments of the injector of the invention incorporate “pain gate” features that reduce perceived discomfort of the injection performed by the injector of the invention. “Pain gate” features of the injector physiologically block pain signals so that such pain signals are reduced and/or eliminated. 
         [0017]    Accordingly, the injector reduces stress, fear, and/or anxiety experienced by the recipient of the injection, particularly those who have needle phobias. 
         [0018]    Needle phobia is a common phenomenon that often results in decreased patient compliance with and patient adherence to medical care. The injector of the invention is likely to reduce induction of needle phobia, as compared with standard syringes and injectors, thereby improving life-long compliance with medical care. In particular, young recipients of injections using the injector of the invention are less likely to develop needle phobias, and thus are less likely to be reluctant to receive medical care throughout life. 
         [0019]    For children who need to receive daily injections, use of the injectors of the invention can reduce conflict and struggle over administration of injections, thereby improving relationships between parents and children. 
         [0020]    Further, use of the injectors of the invention may have beneficial effects on quality of life and/or treatment outcome, generally due to better patient compliance with and adherence to treatment via injections. For example, patients with existing needle phobias are less likely to be traumatized by the injectors of the invention. 
         [0021]    Piercing the skin with a needle is a painful proposition in normal humans and animals. The needle is activating pain receptors in the skin, and this receptor activation is transmitted as a signal to the brain. This pain signal transduction can be reduced by co-activation of mechanoreceptors in the skin. This concept is named the “Pain Gate” mechanism. While conventional standard syringes have no built-in features to activate the “pain gate” mechanism, the injectors of the invention can include such features. For example, the injectors of the invention can have a wide base, and/or can have protrusions from the base of the injector so as to activate the “pain gate” mechanism. The “pain gate” features of the injectors activate the “pain gate” before the needle of the injector pierces the skin, and can maintain activation of the “pain gate” throughout the injection. 
         [0022]    Unlike known syringes and injectors, the injectors of the invention allows pre-selection of the injection site, and then rest on the injection site prior to injection, thereby reducing chances of target selection error. 
         [0023]    Furthermore, the broad palm top of the injectors of the invention eliminates the need for the stabbing motion typically recommended when using known injectors and/or syringes. Consequently, because no stabbing movement is needed, the resulting injection is gentler and less menacing for individuals, particularly those with needle phobias. 
         [0024]    The invention includes an embodiment that is a compact auto-injector device, having at least one concealed needle, the auto-injector device being shaped so as to appear friendly and non-threatening, and being adapted so as to encourage a gentle pressing action for triggering the device. Its friendly and non-threatening shape does not discourage its use. Moreover, the shape is conducive to proper application. It is intuitive to apply the device in the proper orientation, and the orientation does not need to change at any time during operation of the device. Since the shape of the device suggests application in the correct orientation, the possibility of shape-induced confusion regarding application orientation is significantly reduced. 
         [0025]    The injectors of the invention can contain multiple doses of same medication or different medications. 
         [0026]    The injectors of the invention can be convenient for carrying, including carrying in a small pocket, even when containing multiple doses of medication(s). 
         [0027]    One general aspect of the invention is an injector device for injection of a substance into an organism. The injector device includes a mouse-shaped body having: a palm-receiving surface for receiving a palm of a hand, the palm receiving surface being shaped so that the palm is substantially parallel to a surface of an injection site of the organism while operating the device; and at least one button on an exposed surface of the palm-receiving surface, the button being for actuating an injector contained within the mouse-shaped body, the injector having at least one pre-filled syringe, the button being cooperative with the injector such that when pressure is applied to the button, the injector is actuated so as to inject contents of the at least one pre-filled syringe into the injection site of the organism. 
         [0028]    In some embodiments, the mouse-shaped body includes a single button for actuating the injector. In further embodiments, the single button is sized and positioned to be actuated by a finger while the palm-receiving surface receives the palm of the hand. In other further embodiments, the single button is sized and positioned to be actuated by the palm of the hand while the palm-receiving surface receives the palm of the hand. 
         [0029]    In some embodiments, the mouse-shaped body includes two buttons, a first button for releasing a safety mechanism, and a second button for actuating the injector only when the safety mechanism is released. 
         [0030]    In further embodiments, the second button can be actuated by pushing it inward, or by sliding it along the palm-receiving surface. 
         [0031]    In other further embodiments, the two buttons are located one button on the left front top of the mouse-shaped body, and the other button on the right front top of the mouse-shaped body. 
         [0032]    In yet other further embodiments, the two buttons are located one button on the left side of the mouse-shaped body, and the other button on the right side of the mouse-shaped body. 
         [0033]    In still other further embodiments, the two buttons are located one button on the top of the mouse-shaped body, and the other button on the left side of the mouse-shaped body. 
         [0034]    In some embodiments, the button on the top of the mouse-shaped body actuates the injector, and the button on the left side of the mouse-shaped body releases the safety mechanism. 
         [0035]    In some embodiments, the mouse-shaped body includes three buttons, a first button for releasing a safety mechanism, a second button for actuating a first injector only when the safety mechanism is released, and a third button for actuating a second injector only when the safety mechanism is released. 
         [0036]    Another general aspect of the invention is an injector device for injection of a substance into an organism. The device includes: a mouse-shaped body having a palm-receiving surface for receiving a palm of a hand, the palm receiving surface being shaped so that the palm is substantially parallel to a surface of an injection site of the organism while operating the device; and a chassis for supporting an injector contained within the mouse-shaped body, the injector having at least one pre-filled syringe, the chassis also for supporting the palm-receiving surface in spring-loaded compressible relationship, such that when the palm-receiving surface is pushed towards the chassis, the injector is actuated so as to inject contents of the at least one pre-filled syringe into the injection site of the organism. 
         [0037]    In some embodiments, the chassis including a button for releasing a safety mechanism so as to ensure that the injector can be actuated only when the safety mechanism is released. 
         [0038]    In further embodiments, the button can be actuated by pushing it inward, or by sliding it along a surface of the chassis. 
         [0039]    In some embodiments, the palm-receiving surface including a button for releasing a safety mechanism so as to ensure that the injector can be actuated only when the safety mechanism is released. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0040]    The invention will be more fully understood with reference to the Detailed Description, in conjunction with the following figures, wherein: 
           [0041]      FIG. 1A  is a cross-sectional view of an automatic injector having a syringe in side-by-side relationship with an injection/withdrawal mechanism; 
           [0042]      FIG. 1B  is a cross-sectional view of the automatic injector of  FIG. 1A  showing the safety pin removed, making the automatic injector ready for use; 
           [0043]      FIG. 1C  is a cross-sectional view of the automatic injector of  FIG. 1B  showing the trigger pushed in, and the injection/withdrawal mechanism activated; 
           [0044]      FIG. 1D  is a cross-sectional view of the automatic injector of  FIG. 1C  showing the injection needle inserted, and the injection progressing; 
           [0045]      FIG. 1E  is a cross-sectional view of the automatic injector of  FIG. 1D  after the injection has been completed, the withdrawal mechanism having just been activated; 
           [0046]      FIG. 1F  is a cross-sectional view of the automatic injector of  FIG. 1E , showing the main spring collapsed, and the withdrawal spring ready to begin needle withdrawal; 
           [0047]      FIG. 1G  is a cross-sectional view of the automatic injector of  FIG. 1F , showing the injection needle completely withdrawn and hidden inside the body; 
           [0048]      FIG. 2A  is a cross-sectional view of an automatic injector having a syringe in side-by-side relationship with an injection/withdrawal mechanism having a two-stage mode of operation to ensure complete insertion of an injection needle before injection; 
           [0049]      FIG. 2B  is a cross-sectional view of the automatic injector of  FIG. 2A , showing the safety pin removed, making the automatic injector ready for use; 
           [0050]      FIG. 2C  is a cross-sectional view of the automatic injector of  FIG. 2B , showing the trigger pushed in and the injection/withdrawal mechanism activated; 
           [0051]      FIG. 2D  is a cross-sectional view of the automatic injector of  FIG. 2C , showing the injection needle insertion into an injection site in progress; 
           [0052]      FIG. 2E  is a cross-sectional view of the automatic injector of  FIG. 2D , showing the injection just as it is ready to begin as needle insertion progresses; 
           [0053]      FIG. 2F  is a cross-sectional view of the automatic injector of  FIG. 2E , showing the injection in progress after needle insertion has been completed; 
           [0054]      FIG. 2G  is a cross-sectional view of the automatic injector of  FIG. 2F , after the entire dose has been injected, showing the withdrawal mechanism activated; 
           [0055]      FIG. 2H  is a cross-sectional view of the automatic injector of  FIG. 2G , showing the main spring collapsed, and the withdrawal spring ready to withdraw the needle; 
           [0056]      FIG. 2I  is a cross-sectional view of the automatic injector of  FIG. 2H , showing the needle completely withdrawn and hidden inside body; 
           [0057]      FIG. 3A  is a cross-sectional view of a device for palm-controlled operation of a standard syringe, the palm receiving surface of the device being adapted to receive a palm in substantially parallel relationship to a surface of an injection site; 
           [0058]      FIG. 3B  is a cross-sectional view of the device of  FIG. 3A , showing the injection needle partially emerging from the device; 
           [0059]      FIG. 3C  is a cross-sectional view of the device of  FIG. 3B , showing the injection needle completely extending out of the device, also showing injection about to begin; 
           [0060]      FIG. 3D  is a cross-sectional view of the device of  FIG. 3C , showing the injection in progress; 
           [0061]      FIG. 3E  is a cross-sectional view of the device of  FIG. 3D , showing the palm-controlled injection completed; 
           [0062]      FIG. 3F  is a cross-sectional view of the device of  FIG. 3E , showing the device after withdrawal of the palm that operated the device; 
           [0063]      FIG. 4A  is a cross-sectional view of a device for palm-controlled operation of a standard syringe that automatically withdraws the injection needle; 
           [0064]      FIG. 4B  is a cross-sectional view of the device of  FIG. 4A , showing the injection needle partially emerging from the device; 
           [0065]      FIG. 4C  is a cross-sectional view of the device of  FIG. 4B , showing the injection needle completely extended out of the device, and showing the injection ready to begin; 
           [0066]      FIG. 4D  is a cross-sectional view of the device of  FIG. 4C , showing the injection in progress; 
           [0067]      FIG. 4E  is a cross-sectional view of the device of  FIG. 4D , showing the palm-controlled injection completed; 
           [0068]      FIG. 4F  is a cross-sectional view of the device of  FIG. 4E , showing the retrieval of the syringe about to begin; 
           [0069]      FIG. 4G  is a cross-sectional view of the device of  FIG. 4F , showing the device after withdrawal of the palm that operated the device, and showing the injection needle being completely withdrawn; 
           [0070]      FIG. 5A  is a cross-sectional view of a device for simultaneous palm-controlled operation of multiple standard syringes that automatically withdraws the corresponding injection needles; 
           [0071]      FIG. 5B  is a cross-sectional view of the device of  FIG. 5A , showing the palm-controlled injections completed; 
           [0072]      FIG. 6  is a cross-sectional view of a device for simultaneous palm-controlled operation of multiple standard syringes; 
           [0073]      FIG. 7A  is a cross-sectional view of an automatic injector having a syringe in coaxial relationship with an injection/withdrawal mechanism; 
           [0074]      FIG. 7B  is a cross-sectional view of the automatic injector of  FIG. 7A , showing the safety pin removed, making the automatic injector ready for use; 
           [0075]      FIG. 7C  is a cross-sectional view of the automatic injector of  FIG. 7B , showing the top trigger pushed in, and the injection/withdrawal mechanism activated; 
           [0076]      FIG. 7D  is a cross-sectional view of the automatic injector of  FIG. 7C , showing the injection needle inserted, and the injection in progress; 
           [0077]      FIG. 7E  is a cross-sectional view of the automatic injector of  FIG. 7D , showing the device after the injection has been completed, and showing the withdrawal mechanism activated; 
           [0078]      FIG. 7F  is a cross-sectional view of the automatic injector of  FIG. 7E , showing the main spring operation reversed, and showing the start of needle withdrawal; 
           [0079]      FIG. 7G  is a cross-sectional view of the automatic injector of  FIG. 7F , showing the injection needle completely withdrawn; 
           [0080]      FIG. 8A  is a cross-sectional view of a single automatic injector having a syringe in side-by-side relationship with an injection/withdrawal mechanism, the automatic injector to be used in a multi-dose automatic injector; 
           [0081]      FIG. 8B  is a top view of the single automatic injector of  FIG. 8A ; 
           [0082]      FIG. 9A  is a top view of a multi-dose automatic injector having four automatic injectors, each as shown in  FIGS. 8A and 8B ; 
           [0083]      FIG. 9B  is a bottom view of the multi-dose automatic injector of  FIG. 9A , showing the safety pins in overlapping relationship; 
           [0084]      FIG. 10A  is a side view of an automatic palm activated injector, showing use of the automatic palm activated injector by application to a person&#39;s thigh; 
           [0085]      FIG. 10B  is a side view of an automatic palm activated injector, showing use of the automatic palm activated injector by application to a person&#39;s thigh, the injection surface of the automatic palm activated injector being concave so as to substantially fit the convex curvature of the person&#39;s thigh; 
           [0086]      FIG. 11  is a line drawing depicting an automatic palm activated injector being applied to a thigh of a person; 
           [0087]      FIG. 12  is a cross-sectional view of a device for palm-controlled operation of a standard syringe, the palm receiving surface of the device being adapted to receive a palm in substantially perpendicular relationship to a surface of an injection site; 
           [0088]      FIG. 13  is a line drawing depicting an automatic palm activated injector being applied to a thigh of a person with a palm in substantially perpendicular relationship to a surface of an injection site on the thigh; 
           [0089]      FIG. 14  is a top view of a palm-based injector having a single button for actuating a trigger for initiating an automatic injection; 
           [0090]      FIG. 15  is a top view of a palm-based injector having two buttons, one pushable button for actuating a trigger for initiating an automatic injection, and one pushable button for releasing a safety mechanism that must be released to permit the automatic injection; 
           [0091]      FIG. 16  is a top view of a palm-based injector having two buttons, one pushable button for actuating a trigger for initiating an automatic injection, and one slidable button for releasing a safety mechanism that must be released to permit the automatic injection; 
           [0092]      FIG. 17  is a top view of a palm-based injector having two buttons, one pushable button on the left side for actuating a trigger for initiating an automatic injection, and one pushable button on the right side for releasing a safety mechanism that must be released to permit the automatic injection; 
           [0093]      FIG. 18  is a top view of a palm-based injector having three buttons, one pushable button on the top left for actuating a trigger for initiating a first automatic injection, one pushable button on the top right for initiating a second automatic injection, and one slidable button on the left side for releasing a safety mechanism that must be released to permit either automatic injection; 
           [0094]      FIG. 19  is a top view of a palm-based injector having two buttons, one pushable button on the top for actuating a trigger for initiating an automatic injection, and one slidable button on the left side for releasing a safety mechanism that must be released to permit the automatic injection; 
           [0095]      FIG. 20  is a side view of a palm-based injector having palm-receiving surface cooperative with a chassis, where the chassis is in spring-loaded and compressible relationship with the palm-receiving surface so as to initiate an automatic injection when the palm-receiving surface is pressed into the chassis; 
           [0096]      FIG. 21  is a side view of the palm-based injector of  FIG. 20 , further including a slidable button on the palm-receiving surface for releasing a safety mechanism; and 
           [0097]      FIG. 22  is a top view of the palm-based injector of  FIG. 21 . 
       
    
    
     DETAILED DESCRIPTION 
       [0098]    With reference to  FIG. 1A , a syringe  100  has a cylinder  101  containing a substance to be injected, and has a needle  102  and a plunger  104 . A stopper  106  prevents a top arm  108  of a main spring from pushing the plunger  104  into the cylinder  101 . Stopper  106  also prevents syringe  100  from accidentally moving down and exposing the needle  102  through an opening in body  110 . A safety pin  112  prevents a trigger  114  from initiating an injection sequence. To initiate an injection sequence, the safety pin  112  is removed, and the trigger  114  is pushed in. Pushing the trigger  114  in causes the stopper  106  to swing out, thereby enabling the top arm  108  of the main spring to push the plunger  104  downward. When plunger  104  reaches a retrieval trigger  116 , a bottom arm  118  of main spring will be free to move up and enable a retrieval spring  120  to rotate around an axle  122 . An interlocking spring  124  will interlock plunger  104  with cylinder  101 , when plunger  104  is fully inserted in cylinder  101 . All of the parts contained within the body  110  are referred to as an injector  126 , which includes the syringe  100 , and other parts described above that cooperate so as to perform an injection using the syringe  100 . The body  110  has a palm-receiving surface  128  that receives a palm of a hand. The palm-receiving surface  128  is cooperative with the injector  126  to as to provide a palm-controlled device  130  for injection of a substance into an injection site of an organism. The palm-receiving surface  128  is shaped to receive a palm of a hand so that when the palm of the hand that is used to operate the palm-controlled device  130 , the palm must be substantially parallel to a surface of the injection site. When pressure is applied to the palm-receiving surface  128 , the injector  126  is actuated so as to inject the contents of at least one pre-filled syringe of the injector into the injection site. The organism can be a human or an animal. 
         [0099]    With reference to  FIG. 1B , prior to removal of safety pin  112 , the trigger  114  cannot be pushed in when pressure is applied to the palm-receiving surface  128 . Consequently, the injector  126  cannot be actuated, and no injection can occur. When the safety pin  112  is removed from the body  110 , the device  130  is ready for use. Stopper  106  still prevents the top arm  108  of the main spring from pushing down the plunger  104 . The stopper  106  also holds the cylinder  101  from accidentally moving down, thereby exposing the injection needle  102 . 
         [0100]    With reference to  FIG. 1C , body  110  is pressed against the intended injection site of an organism, thereby pushing trigger  114  into body  110 . Trigger  114  pushes stopper  106  out of the way, thereby enabling the top arm  108  of the main spring to push the plunger  104  downward. Due to natural viscosity and lack of compressibility of the liquid substance in the cylinder  101 , pressing on the plunger  104  causes the cylinder  101  to move downward, along with the needle  102 , thereby causing the needle  102  to move through the opening in body  110 . Once the needle emerges from the hole in the body  110 , it begins to enter the injection site of the organism. 
         [0101]    With reference to  FIG. 1D , when cylinder  101  contacts the body  110 , the needle  102  has completely emerged from the body  110 . Then, the top arm  108  of the main spring continues to push the plunger  104  into the cylinder  101 , causing injection of the substance through the needle  102  until the plunger  104  activates the withdrawal trigger  116 . 
         [0102]    With reference to  FIG. 1E , top arm  108  of the main spring continues to push plunger  104  to cause the interlocking spring  124  of the plunger  104  to latch onto the cylinder  101 . The top arm  108  of the main spring continues to push, causing injection of all of the substance. When both the plunger  104  and the cylinder  101  have each reached the full travel, the plunger  104  activates withdrawal trigger  116 . Activation of withdrawal trigger  116  releases bottom arm  118  of the main spring. Withdrawal spring  120  rests on the bottom arm  118  of the main spring. The withdrawal spring  120  is now free to push both the bottom arm  118  and the top arm  108  of the main spring upward. 
         [0103]    With reference to  FIG. 1F , the bottom arm  118  of the main spring moves up and rests against the top arm  108  of the main spring. Withdrawal spring  120  rests on the bottom arm  118  of the main spring. The withdrawal spring  120  is now free to push the bottom arm  118  of the main spring against the top arm  108  of the main spring, to cause the main spring to rotate around axle  122 , which will lift the plunger  104 . Since the interlocking spring  124  of the plunger  104  is in latched relationship with the cylinder  101 , the cylinder  101  will be lifted along with the plunger  104 . Lifting the cylinder  101  will lift the injection needle  102  upwards, withdrawing the injection needle  102  back into the body  110  of the palm controlled device  130 . 
         [0104]    With reference to  FIG. 1G , withdrawal spring  120  rotates both bottom arm  118  of the main spring and top arm  108  of the main spring around the axle  122 . Rotation of the top arm  108  of the main spring pulls plunger  104  upward. Since the interlocking spring  124  of the plunger  104  is in latched relationship with the cylinder  101 , the cylinder  101  is lifted along with the plunger  104 . Lifting the cylinder  101  lifts the injection needle  102  upwards, thereby withdrawing the injection needle  102  back into the body  110  of the palm controlled device  130 . 
         [0105]    With reference to  FIG. 2A , a syringe  200  has a cylinder  202  containing a substance to be injected, and has an injection needle  204  and a plunger  206 . Retainer  208  prevents relative movement between plunger  206  and the cylinder  202 . A stopper  210  prevents a top arm  212  of a main spring from pushing the plunger  206 , the retainer  208 , the cylinder  202 , and the injection needle  204  downward. Stopper  210  prevents syringe  200  from accidentally moving down, thereby preventing exposure of the needle  204  through an opening in body  214 , so as to prevent needle stick accidents. A safety pin  216  prevents a trigger  218  from initiating an injection sequence. To initiate an injection sequence, the safety pin  216  is removed, and pressure applied by the palm of a hand onto the palm-receiving surface  220  of the body  214  causes body  214  to press against the injection area containing the intended injection site of the organism. The counter-pressure of the injection area pushes the trigger  218  inward. Pushing the trigger  218  inward causes the stopper  210  to swing out, thereby enabling the top arm  212  of the main spring to push the plunger  206  downward. Retainer  208  prevents the plunger  206  from entering the cylinder  202 . Retainer  208  is free to glide along straight edge  222  of the body  214  until the retainer  208  is pushed into an open area  224 , thereby permitting the plunger  206  to move further into the cylinder  202 . When plunger  206  reaches a retrieval trigger  226 , a bottom arm  228  of the main spring will be free to move up and enable a retrieval spring  230  to rotate about an axle  232 . An interlocking spring  234  will interlock the plunger  206  with the cylinder  202 , when plunger  206  is fully inserted in cylinder  202 . All of the parts contained within the body  214  are referred to as an injector  236 , which includes the syringe  200 , and other parts described above that cooperate so as to perform an injection using the syringe  200 . The body  214  has a palm-receiving surface  220  that receives a palm of a hand. The palm-receiving surface  220  is cooperative with the injector  236  so as to provide a palm-controlled device  238  for injection of a substance into an injection site of an organism. The palm-receiving surface  220  is shaped to receive a palm of a hand so that when the palm of the hand that is used to operate the palm-controlled device  238 , the palm must be substantially parallel to a surface of the injection site. When pressure is applied to the palm-receiving surface  220 , the injector  236  is actuated so as to inject the contents of at least one pre-filled syringe  200  of the injector  236  into the injection site. The organism can be a human or an animal. 
         [0106]    With reference to  FIG. 2B , prior to removal of safety pin  216 , the trigger  218  cannot be pushed in when pressure is applied to the palm-receiving surface  220 . Consequently, the injector  236  cannot be actuated, and no injection can occur. When the safety pin  216  is removed from the body  214 , the device  238  is ready for use. Stopper  210  still prevents the top arm  212  of the main spring from pushing down the plunger  206 , the retainer  208 , and the cylinder  202 , thereby pushing the injection needle  204  out of the body  214 . 
         [0107]    With reference to  FIG. 2C , the body  214  is pressed against the intended injection area, thereby moving the trigger  218  into the body  214 . Trigger  218  pushes the stopper  210  out of the way, and enables the top arm  212  of the main spring to push the plunger  206 . Retainer  208  can glide vertically alongside a straight edge  222  of the body  214 , thereby forcing the cylinder  202  to move down together with the plunger  206  to begin insertion of the needle  204  into the organism. 
         [0108]    With reference to  FIG. 2D , the top arm  212  of the main spring pushes the plunger  206  down. The retainer  208  prevents relative motion between the plunger  206  and cylinder  202 , thereby pushing the cylinder  202  down. The needle  204  protrudes from the body  214  and into the organism. 
         [0109]    With reference to  FIG. 2E , top arm  212  of the main spring pushes the plunger  206  and the retainer  208  down until the retainer  208  is pushed past the straight edge  222  and into the open area  224  in the body  214 . The retainer  208 , having been pushed out of place, no longer prevents relative movement between the plunger  206  and the cylinder  202 . 
         [0110]    With reference to  FIG. 2F , the top arm  212  of the main spring continues to push the plunger  206 . While injecting, the natural viscosity and incompressibility of the fluid contained in the cylinder  202 , together with the small resistance of the interlocking spring  234  continue to push the cylinder  202  and the injection needle  204  out of the body  214 . 
         [0111]    With reference to  FIG. 2G , top arm  212  of the main spring continues to push the plunger  206 , and the plunger  206  continues to push the cylinder  202  down so that the interlocking spring  234  of the plunger  206  latches onto the cylinder  202 . Top arm  212  of the main spring continues to push down on the plunger  206  until the plunger  206  is fully inserted into the cylinder  202 , and the injection needle  204  has completely emerged from the body  214 . The plunger  204  activates withdrawal trigger  226 . Activation of the withdrawal trigger  226  releases the bottom arm  228  of the main spring. The withdrawal spring  230  rests on the bottom arm  228  of the main spring, and the withdrawal spring  230  is now free to push up the bottom arm  228  of the main spring. 
         [0112]    With reference to  FIG. 2H , the withdrawal spring  230  pushes the bottom arm  228  of the main spring up against the top arm  212  of the main spring, thereby causing the main spring to rotate about the axle  232 . The top arm  212  of the main spring pulls the plunger  206  upward. The plunger  206  is interlocked with the cylinder  202  because of the interlocking spring  234 , thereby pulling the cylinder  202  upward. Pulling the cylinder  202  upward causes withdrawal of the injection needle  204  into the body  214 . 
         [0113]    With reference to  FIG. 2I , the withdrawal spring  230  rotates both the bottom arm  228  of the main spring and the top arm  212  of the main spring about the axle  232 . Rotation of the top arm  212  of the main spring pulls the plunger  206  upward. The interlocking spring  234  latches plunger  206  to the cylinder  202 . Pulling the plunger  206  upward also pulls the cylinder  202  upward. Since the injection needle  204  is connected to the cylinder  202 , the injection needle  204  is withdrawn completely into the body  214  of the device  238 . 
         [0114]    An embodiment of a Single-dose Palm-controlled Injector of the invention is now disclosed. Daily home-based administration of medications has gained widespread use, including growth hormones, insulin, heparin, antibiotics, IVF hormones, for example. Caregivers and patients are often intimidated by the stab-like motion of the injection, and the pain inflicted thereby. Consequently, there is reluctance and commotion associated with administration of injections using known injectors in many households. The Single-dose Palm-controlled Injector of the invention employs a palm-controlled method of injection, as well as “pain gate” activation features, to provide a more comfortable experience of needed injections. 
         [0115]    With reference to  FIG. 3A , a syringe  300 , having a plunger  302 , a cylinder  304 , and an injection needle  306 , is releasably and slidably held by syringe holders  308 . The syringe holders  308  are attached to the base  310 . The base  310  includes guide tracks  312 . The bottom of the base  310  contacts an injection area of the organism to be injected, and the injection site falls within the injection area. The bottom of the base  310  includes a hole  314  which allows the injection needle  306  to pass through. The bottom of the base  310  also can include at least one pain gate feature  316 , such as a substantially flat surface with gently rounded edges, or a plurality of bumps, or a plurality of ridges, such as concentric ridges, or straight ridges, or S-shaped ridges, or L-shaped ridges, or radial ridges. The guide tracks  312  constrain movement of rollers  318 , each roller  318  being rotatably attached to a respective arm  320 . Each arm  320  is hingedly attached to a top  322 , the top  322  having a palm-receiving surface  324 . The palm-receiving surface  324  receives pressure as applied by a palm of a hand, the palm-receiving surface  324  being shaped so that the palm is substantially parallel to a surface of an injection site of an organism while operating the device. The top  322  is in slidable relationship with the base  310 , the top  322  being movable along spring tracks  326 . The springs  328  apply a restoring force between the top  322  and the base  310  when the top  322  is pressed by a palm towards the base  310 . All of the parts  308 - 320  and  326 - 328  are referred to as an injector, which parts cooperate so as to perform an injection using the syringe  300 . The top  322  has a palm-receiving surface  324  that receives a palm of a hand. The palm-receiving surface  324  is cooperative with the injector to as to provide a palm-controlled device  330  for injection of a substance into an injection site of an organism. 
         [0116]    With reference to  FIG. 3B , a palm of a hand presses onto the palm-receiving surface  324  of the top  322 , thereby applying pressure to the injection area having the injection site, the pressure being applied via the pain gate features  316  of the base  310 . The pressure also pushes arms  320  downward, thereby causing the arms  320  with rollers  318  to glide along path  312 , the rollers  318  pushing the cylinder  304 , thereby causing the syringe  300  to slide through the syringe holders  308 , and causing the injection needle  306  to emerge from the hole  314 . The top  322  does not touch the plunger  302 , and so the injection needle  306  is being inserted into the injection site, without injecting the substance. The movement of the top  322  relative to the base  310  is resisted by the springs  328 , causing the springs to be further stretched, thereby accumulating potential energy that will restore the top to its original position when the palm is removed. 
         [0117]    With reference to  FIG. 3C , the palm continues to press on the palm receiving surface  324  of the top  322 , thereby moving the cylinder  304  until it reaches the end of its travel caused by the arms  320 . The travel caused by the arms  320  ends when the rollers  318  spread wider than the width of the top end of the cylinder  304 . The rollers  318  are led by the arms  320 , the arms  320  being led by the path  312 . Further, because the rollers have lost contact with the cylinder  304 , further pushing of the top  322  will result in an inner surface of the top  322  pushing the plunger  302  into the cylinder  304 . 
         [0118]    With reference to  FIG. 3D , the end of each arm  320  is guided by the paths  312 , causing the rollers  318  to no longer contact the top the cylinder  304 , while the inner surface of the top  322  pushes the plunger  302  into the cylinder  304 , thereby causing injection of the substance into the injection site. 
         [0119]    With reference to  FIG. 3E , the top  322  has reached the lowest point in its travel, and the plunger  302  has reached the end of its travel within the cylinder  304 , and the springs  328  have reached their maximum extension. As a result of the plunger  302  reaching the end of its travel within the cylinder  304 , the injection of the substance is completed. 
         [0120]    With reference to  FIG. 3F , when the pressure of the palm upon the palm receiving surface  324  of the top  322  is removed, the springs  328  are allowed to return their initial pre-loaded state. The contraction of the springs  328  drives the top  322  to return to its initial position. In this embodiment, we recommend using a syringe that automatically withdraws the injection needle into the syringe after injection of the substance is completed. 
         [0121]    With reference to  FIG. 4A , a syringe  400 , having a plunger  402 , a cylinder  404 , and an injection needle  406 , is releasably and slidably held by syringe holders  408 . The syringe holders  408  are attached to the base  410 . The base  410  includes guide tracks  412 . The bottom of the base  410  contacts an injection area of the organism to be injected, and the injection site falls within the injection area. The bottom of the base  410  includes a hole  414  which allows the injection needle  406  to pass through. The bottom of the base  410  also can include at least one pain gate feature  416 , such as a substantially flat surface with gently rounded edges, or a plurality of bumps, or a plurality of ridges, such as concentric ridges, or straight ridges, or S-shaped ridges, or L-shaped ridges, or radial ridges. The guide tracks  412  constrain movement of rollers  418 , each roller  418  being rotatably attached to a respective arm  420 . Each arm  420  is hingedly attached to a top  422 , the top  422  having a palm-receiving surface  424 . The palm-receiving surface  424  receives pressure as applied by a palm of a hand, the palm-receiving surface  424  being shaped so that the palm is substantially parallel to a surface of an injection site of an organism while operating the device. The top  422  is in slidable relationship with the base  410 , the top  422  being movable along spring tracks  426 . The springs  428  apply a restoring force between the top  422  and the base  410  when the top  422  is pressed by a palm towards the base  410 . All of the parts  408 - 420  and  426 - 428  are referred to as an injector, which parts cooperate so as to perform an injection using the syringe  400 . The top  422  has a palm-receiving surface  424  that receives a palm of a hand, cutouts  432 , and syringe retrievers  434  that are free to move along the cutouts  432 . The syringe retrievers  434  retrieve the cylinder  404  as the top  422  returns to its initial position. The palm-receiving surface  424  is cooperative with the injector to as to provide a palm-controlled device  430  for injection of a substance into an injection site of an organism. While top  422  returns to its initial position, the syringe retrievers  434  reach the end of the cutouts  432  in the top  422 , the syringe retrievers  434  thereby beginning retrieving the cylinder  404 . As the syringe retrievers  434  move, they pull the cylinder  404 , thereby pulling the needle  406  into the base  410 . 
         [0122]    With reference to  FIG. 4B , a palm of a hand presses onto the palm-receiving surface  424  of the top  422 , thereby applying pressure to the injection area having the injection site, the pressure being applied via the pain gate features  416  of the base  410 . The pressure also pushes arms  420  downward, thereby causing the arms  420  with rollers  418  to glide along the path  412 , the rollers  418  pushing the cylinder  404 , thereby causing the syringe  400  to slide through the syringe holders  408 , and causing the injection needle  406  to emerge from the hole  414 . The top  422  does not touch the plunger  402 , and so the injection needle  406  is being inserted into the injection site, without injecting the substance. The movement of the top  422  relative to the base  410  is resisted by the springs  428 , causing the springs to be further stretched, thereby accumulating potential energy that will restore the top  422  to its original position when the palm is removed. 
         [0123]    With reference to  FIG. 4C , the palm continues to press on the palm receiving surface  424  of the top  422 , thereby moving the cylinder  404  until it reaches the end of its travel caused by the arms  420 . The travel caused by the arms  420  ends when the rollers  418  spread wider than the width of the top end of the cylinder  404 . The rollers  418  are led by the arms  420 , the arms  420  being led by the path  412 . Further, because the rollers  418  have lost contact with the cylinder  404 , further pushing of the top  422  will result in an inner surface of the top  422  pushing the plunger  402  into the cylinder  404 . 
         [0124]    With reference to  FIG. 4D , the end of each arm  420  is guided by the paths  412 , causing the rollers  418  to no longer contact the top the cylinder  404 , while the inner surface of the top  422  pushes the plunger  402  into the cylinder  404 , thereby causing injection of the substance into the injection site. Because of the cutouts  432  in the top  422 , the syringe retrievers  434  do not restrict relative movement between the top  422  and the cylinder  404 . 
         [0125]    With reference to  FIG. 4E , the top  422  has reached the lowest point in its travel, and the plunger  402  has reached the end of its travel within the cylinder  404 , and the springs  428  have reached their maximum extension. As a result of the plunger  402  reaching the end of it&#39;s travel within the cylinder  404 , the injection of the substance is completed. 
         [0126]    With reference to  FIG. 4F , while top  422  returns to its initial position, the syringe retrievers  434  reach the end of the cutouts  432  in the top  422 , the syringe retrievers  434  thereby beginning retrieving the cylinder  404 . When the syringe retrievers  434  begin to move, they will pull the cylinder  404 , thereby pulling the needle  406  into the base  410 . 
         [0127]    With reference to  FIG. 4G , when the pressure of the palm upon the palm receiving surface  424  of the top  422  is removed, the springs  428  are allowed to return their initial pre-loaded state. The contraction of the springs  428  drives the top  422  to return to its initial position. In this embodiment, a standard syringe can be used. Once the top  422  has returned to its initial position, the syringe retrievers  434  have reached the end of the cutouts  432  in the top  422 , and consequently the syringe retrievers  434  have retrieved the cylinder  404 , thereby pulling the needle  406  completely into the base  410 . 
         [0128]    An embodiment of a Simultaneous Multi-dose Palm-controlled Injector of the invention is now disclosed. Immunization schedules for infants are recommended by both the Centers for Disease Control and the American Academy of Pediatrics. These immunization schedules recommend administration of multiple vaccinations, which require a sequence of injections during each of three office visits, the injections occurring at two, four, and six months of age, and at one year, and at 18 months of age. During each vaccination visit, an infant may receive from two to six injections. This may result in anxiety for both the parents and the child, before, during, and after the visits, which may also interfere with the relationship between the parents and the healthcare provider. Furthermore, this is thought to contribute to excessive anxiety in children upon entering a medical office, and may also contribute to tendency towards life-long needle-phobia and/or doctor phobia (“White Coat Syndrome”). 
         [0129]    Beyond immunization schedules, there are other medical conditions that require administration of a variety of injectable medications. As presently administered, a sequence of such injections can result in excessive anxiety, discomfort, fear, and pain. 
         [0130]    The palm-controlled injector of the invention enables simultaneous multiple injections, thereby reducing for the patient the time, anxiety, and discomfort due to the injections, as compared with performing the injections sequentially. The proposed injector includes features that activate the “pain gate” effect, and is consequently likely to inflict less pain as compared with known injectors. Simultaneous administration of multiple injections is also likely to reduce for parents and caregivers the anxiety and frustrations associated with the injections, as compared with performing the injections sequentially. Furthermore, the simultaneous administration performed by the injector of the invention will result in time saved per patient, both from actual administration of the injections simultaneously, and from the reduced time spent to overcome patient resistance and struggle typically associated with multiple injections, leading to substantially improved efficiencies in the operation of medical facilities. 
         [0131]    With reference to  FIG. 5A , the device  500  is similar to the device  430  shown in  FIG. 4  in both structure and function, one difference being that device  500  can accommodate a plurality of syringes  400 . Consequently, the top  502  has a plurality of pairs of cutouts  504  to accommodate a respective plurality of retrievers  434 . Alternatively, the top  502  can have a plurality of single cutouts (not shown) to accommodate a respective plurality of retrievers (not shown), each retriever having two prongs to symmetrically pull each syringe  400 , and a single prong to follow each single cutout (not shown). Another difference is that the arms  420 , that hold the rollers  418 , push upon a plate  506  that in turn pushes each of the syringes  400 . The plate  506  includes a plurality of openings, each opening allowing a respective plunger to move unrestrictedly. The inner surface of the top  502  includes a plurality of bumps  508  capable of pushing respective plungers  402  unrestrictedly through the openings in the plate  506 . Also, the base  510  includes a plurality of openings  414 , to accommodate the respective plurality of syringes  400 . Yet another difference, unrelated to the fact that the device  500  can accommodate a plurality of syringes  400 , is that the cutouts  504  are shorter than the cutouts  432  shown in  FIG. 4 . Further, the retrievers  434  must travel along the length of the syringes  400  to accommodate for lesser travel range in each of the cutouts  504 . 
         [0132]    With reference to  FIG. 5B , at the end of the full travel range of the device  500 , each retriever  434  resides at the top end of the respective cutout  504 , and each retriever  434  slides along the respective syringe  400  so as to accommodate for the lesser travel range in each of the cutouts  504 . Further, the syringe holders  408  are located so as to not interfere with the travel of the retrievers  434 . 
         [0133]    With reference to  FIG. 6 , the device  600  is similar to the device  500  shown in  FIG. 5  in both structure and function, one difference being that device  600  does not include any retrievers  434 , and does not include any cutouts  504 . In this embodiment, we recommend using syringes that automatically withdraw the injection needle into each syringe after injection is completed. 
         [0134]    With reference to  FIG. 7A , a syringe  700  has a cylinder  702  containing a substance to be injected, and has an injection needle  704  and a plunger  706 . The sharp end of the injection needle  704  is protected by a protective barrier  708  that prevents the substance from leaking out of the syringe  700 . The protective barrier  708  also maintains the injection needle  704  in a clean condition. The protective barrier  708  also prevents the cylinder  702  and the injection needle  704  from accidentally separating from the plunger  706 , thereby inadvertently exposing the injection needle  704 . 
         [0135]    The plunger  706  has arms  710  with latching springs  712 . When the plunger  706  travels fully into the cylinder  702 , the latching springs  712  latch onto the cylinder  702 , so as to ensure that the plunger  706 , the cylinder  702 , and the injection needle  704  move together during retraction of the syringe  700 . 
         [0136]    The top of a spring  714  presses against the top portion of the spring retainers  716 , while the bottom of the spring  714  presses against the plunger reversal brackets  718 . Each plunger reversal bracket  718  leans against the plunger  706 , and leans against a respective spring retainer  716 , thereby preventing the spring retainers  716  from moving inwards. The inner surface of the body  720  is shaped so as to prevent the spring retainers  716  from moving upwards unless the spring retainers  716  can also move inwards. The spring retainers  716  cannot move inwards, and therefore cannot move upwards, because the plunger reversal brackets  718  block inwards movement of the spring retainers  716 . The pressure exerted by the preloaded spring  714  against the plunger reversal brackets  718  resting on a ledge of the plunger  706  stabilizes the plunger reversal brackets  718  and the spring retainers  716 , while allowing a mutually sliding relationship between the plunger reversal brackets  718  and the spring retainers  716 . 
         [0137]    The pre-loaded spring  714  would cause the plunger  706  and the plunger reversal brackets  718  to slide along the spring retainers  716 , but for the swivel releases  722  that prevent the plunger  706  from moving. 
         [0138]    A safety  724  prevents a top trigger  726  having a palm receiving surface  728  from compressing a safety spring  730 , and then causing the swivel releases  722  to release the plunger  706  to move in response to the pressure exerted by the preloaded spring  714 . 
         [0139]    Pressure upon the palm receiving surface  728  thus causes the device  732  to initiate insertion of the injection needle  704  through the hole  734  and into an injection site, and then to further inject the substance into the injection site, followed by automatic retraction of the injection needle  704  back into the body  720 . Additionally, pressure upon the palm receiving surface  728  causes the body  720  to press the pain gating elements  736  against the periphery of the injection site, thereby activating a pain gate effect that reduces discomfort associated with the injection. 
         [0140]    With reference to  FIG. 7B , removing the safety  724  allows the top trigger  726  to compress the safety spring  730 , compression of the safety spring  730  allowing the top trigger  726  to cause the swivel releases  722  to release the plunger  706  so that the plunger  706  can move in response to the pressure exerted by the preloaded spring  714 . 
         [0141]    With reference to  FIG. 7C , pressure of a palm upon the palm receiving surface  728  caused the top trigger  726  to compress the safety spring  730 , and causes the top trigger  726  to press upon the swivel releases  722  so as to release the plunger  706 . 
         [0142]    With reference to  FIG. 7D , the top of the spring  714  presses against the top portion of the spring retainers  716 , while the bottom of the spring  714  presses against the plunger reversal brackets  718 . The plunger reversal brackets  718  press against the ledge of the plunger  706 , causing movement of the plunger  706 . Movement of the plunger  706  causes cylinder  702  to move towards the hole  734 , also causing the injection needle  704  to move through the hole  734 , after penetrating through the protective barrier  708 . Due to natural viscosity and lack of compressibility of the liquid substance in the cylinder  101 , pressing on the plunger  706  causes the cylinder  702  to move towards the hole  734 , along with the injection needle  704 , thereby causing the injection needle  704  to move through the protection barrier  708  and then through the hole  734 . Once the injection needle  704  emerges from the hole  734 , it begins to enter the injection site of the organism. 
         [0143]    With reference to  7 E, the cylinder  702  is shown reaching the end of its travel within the body  720 , thereby compressing the protective barrier  708 , and the plunger  706  is shown reaching the end of its travel within the cylinder  702 . While the plunger  706  moves inside the cylinder  702 , the latching arms  710  move along the outside of the cylinder  702 . Before the plunger  706  reaches the end of its travel with the cylinder  702 , the latching spring  712  of each latching arm  710  latches onto the cylinder  702  so as to cause the cylinder to move away from the hole  734  when the plunger  706  moves away from the hole  734  during retraction of the syringe  700 . 
         [0144]    When the spring  714  pushes the plunger reversal brackets  718  past the edge of the spring retainers  716 , the spring retainers  716  no longer hold the plunger reversal brackets  718  in place, thereby causing the plunger reversal brackets  718  to be pushed out of place by the spring  714 . When the spring reversal brackets  718  fall out of place, the bottom of the spring  714  no longer pushes on the plunger, instead pushing upon a confronting inner surface of the body  720 . 
         [0145]    With reference to  FIG. 7F , the top of the spring  714  pushes the spring retainers  716  up and away, thereby allowing the top of the spring  714  to push against the top of the plunger  706 . Pressure exerted by the spring  714  upon the confronting inner surface of the body  720 , and upon the top of the plunger  706  causes retraction of the syringe  700 . 
         [0146]    With reference to  FIG. 7G , the device  732  is shown in a retracted state, after both injection of the substance by the syringe  700 , and the subsequent retraction of the syringe  700 . The safety spring  730  can remain compressed due to pressure upon the palm receiving surface  728  during both injection and retraction. Alternatively, momentary pressure upon the palm receiving surface  728  can serve to trigger the device  732 , thereafter allowing the safety spring  730  to be in an expanded state during both injection and retraction. 
         [0147]    With reference to  FIG. 8A , the mechanism as described in  FIG. 1  is shown as a single automatic injector for use in a multi-dose automatic injector, as shown in  FIG. 9 , and described herein below. 
         [0148]    With reference to  FIG. 8B , a top view of the single automatic injector of  FIG. 8  is shown. 
         [0149]    An embodiment of a Sequential Multi-dose Palm-controlled Injector of the invention is now disclosed. Known emergency auto-injectors can include up to two doses of a single medication. However, at times, a need may arise for administration of more than two doses of the medication. For example, patients with food allergies may require more than two doses of epinephrine for multiple occurrences of an allergic reaction. Currently, patients are advised to carry two EpiPens® or one TwinJect® having two doses of epinephrine at all times. However, while a patient is on a flight, for example he/she may react to two different foods at two respective times during the flight, and so he/she may require more than two doses of epinephrine. Also, parents with multiple children, more than one having food allergies, can benefit from a single device with more than two doses of epinephrine. The co-administration of a pair of medications is a common occurrence, such as the co-administration of antihistamine with epinephrine. The auto-injector of the invention can be used so as to administer multiple paired doses of different medications. Thus, if a patient with multiple food allergies experiences a sequence of allergic reactions during a flight, and consequently requires co-administered injections of both antihistamine and epinephrine, the emergency auto-injector of the invention can provide a plurality of co-administered doses. 
         [0150]    With reference to  FIG. 9A , body  900  contains four separately operated automatic injectors  902 A,  902 B,  902 C, and  902 D, each as described in  FIG. 8  and  FIG. 8A , arranged so as to minimize required space within the body  900 . Removal of a safety pin  112 A of the injector  902 A, enables removal of the safety pin  112 B of the second automatic injector  902 B. Removal of a safety pin  112 B of the injector  902 B, enables removal of the safety pin  112 C of the third automatic injector  902 C. Removal of a safety pin  112 C of the injector  902 C, enables removal of the safety pin  112 D of the fourth automatic injector  902 D. 
         [0151]    With reference to  FIG. 9B , the bottom of the body  900  is shown, so as to show the bottom of each of the four safety pins  112 A,  112 B,  112 C,  112 D. The bottoms of each of the safety pins  112 A,  112 B,  112 C,  112 D overlap, so as to enforce the sequential enablement of actuation of the plurality of automatic injectors  902 A,  902 B,  902 C, and  902 D. 
         [0152]    With reference to  FIG. 10A , an automatic palm activated injector  1000  is held in place on a thigh  1002  by a palm of a hand  1004 . With reference to  FIG. 10B , an automatic palm activated injector  1006  has a concave injection surface  1008  that fits more closely to a convex injection site than a flat injection surface, as illustrated. 
         [0153]    With reference to  FIG. 11 , a person is shown applying an automatic palm activated injector  1100  with a palm of a hand  1102  to a thigh  1104  by holding and slightly pressing upon the injector  1100  with a palm of the hand  1102  in substantially parallel relationship with respect to an injection site of an organism while operating the device. 
         [0154]    With reference to  FIG. 12 , a device  1200  is shown, similar to the device  330  shown in  FIG. 3 , except that the palm receiving surface  1202  of the top  1204  is shaped so as to receive a palm in substantially perpendicular relationship with respect to an injection site of an organism while operating the device. 
         [0155]    With reference to  FIG. 13 , a person is shown applying an automatic palm activated injector  1300  with a palm of a hand  1302  to a thigh  1304  by holding and slightly pressing upon the injector  1300  with a palm of the hand  1302  in substantially perpendicular relationship with respect to an injection site of an organism while operating the device. 
         [0156]    With reference to  FIG. 14 , a mouse-shaped body  1400  includes a palm-receiving surface  1402  and a button  1404  for actuating an injector mechanism (not shown) inside the mouse-shaped body  1400 . The mouse-shaped body  1400  is placed gently and slowly upon the leg, for example, and then can be slid along the leg so as to precisely position the body  1400  at the desired location for injection. Once at the desired location, the palm of the user steadies the body  1400  via contact with the surface  1402 , while the finger of the user presses the button  1404 . 
         [0157]    With reference to  FIG. 15 , a mouse-shaped body  1500  having a palm-receiving surface  1502 , a right button  1504  for releasing a safety mechanism, and a left button  1506  for actuating the injector. Unless the safety mechanism is released, the injector cannot be actuated, protecting the user from unintended injection. The safety can be released via the button  1504  after the body  1500  has been placed at the desired location. Then pressing the button  1506  initiates the injection. 
         [0158]    Referring to  FIG. 16 , the mouse-shaped body  1600  has a palm-receiving surface  1602 , a button  1604  that slides to release a safety mechanism, and a button  1606  that can be pushed to actuate the injection. 
         [0159]    Referring to  FIG. 17 , the mouse-shaped body  1700  has a palm-receiving surface  1702 , a pushable button on the left side  1703  for actuating an injection, and a pushable button on the right side  1704  for releasing a safety mechanism. The button  1704  can either be pressed before pressing  1703 , or can be configured to be pressed simultaneously with the button  1703 . Referring to  FIG. 18 , the mouse-shaped body  1800  has a palm-receiving surface  1802 , a pushable button on the top right side  1804  for actuating a first injector within the mouse-shaped body  1800 , a pushable button on the top left side  1805  for actuating a second injector within the mouse-shaped body  1800 , and slidable button  1806  for releasing a safety mechanism. The button  1806  can be slid forward to release the safety for the first injector and lock the safety of the second injector, and can be slid backward to release the safety for the second injector, also locking the first injector. 
         [0160]    Referring to  FIG. 19 , the mouse-shaped body  1900  has a palm-receiving surface  1902 , a pushable button on the top side  1904  for actuating an injector within the mouse-shaped body  1909 , and slidable button  1905  for releasing a safety mechanism. The button  1905  has friction ridges  1906  to facilitate sliding of the button  1905 . The button  1905  can be slid forward to release the safety for the first injector, and can be slid backward to lock the safety for the first injector. 
         [0161]    Referring to  FIG. 20 , the mouse-shaped body  2000  has a palm-receiving surface  2002  and a chassis  2004  that is in spring-loaded relationship with the surface  2002 . To use this embodiment, the user places the body  2000  at the desired injection site, and then presses on the palm-receiving surface  2002  with his/her palm to urge the surface  2002  towards the chassis  2004 , thereby initiating an injection. 
         [0162]    Referring to  FIG. 21 , the mouse-shaped body  2000  has a palm-receiving surface  2002  and a chassis  2004  that is in spring-loaded relationship with the surface  2002 , also including a sliding button  2100  that controls a safety mechanism that prevents injection unless the user slides the button  2100 . To use this embodiment, the user places the body  2000  at the desired injection site, and then slides the button  2100  to release the safety mechanism. Then, the user presses on the palm-receiving surface  2002  with his/her palm to urge the surface  2002  towards the chassis  2004 , thereby initiating an injection. 
         [0163]    With reference to  FIG. 22 , this is a top view of the embodiment of  FIG. 21 , showing the chassis  2004  below the palm-receiving surface  2002 , and the sliding button  2100 . 
         [0164]    Other modifications and implementations will occur to those skilled in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the above description is not intended to limit the invention except as indicated in the following claims.