CN109200398B - Apparatus for removing a medical sharp from a holder - Google Patents

Abstract

An apparatus for removing a medical sharp from a holder, induction heating from an induction coil (108) being used to separate a metallic medical sharp (144) from its holder (142) by applying a high frequency oscillating magnetic field which induces eddy currents and resistive heating in the sharp. The heated metal sharp causes the adhesive or plastic securing the sharp to its holder to melt. The use of induction heating is advantageous because it does not require direct contact between the circuit and the sharps or its holder. The heating may also act to sterilise the sharps and thus make them less dangerous as it separates the sharps from its holder. The induction coil may have a stepped shape or a conical shape to concentrate the radio frequency energy at the interface between the metal sharp and its holder.

Description

Apparatus for removing a medical sharp from a holder

This application claims priority from U.S. provisional patent application No. 62/529,926 filed on 7.7.2017 and entitled "Medical Sharp Removal and Storage Device" and U.S. provisional patent application No. 62/530,001 filed on 7.7.2017 and entitled "Induction Heating Circuit for Medical Sharp Removal Device", the entire contents of both of which are expressly incorporated herein by reference.

Technical Field

The present invention relates generally to an electrical control circuit for use with such a device: the device is used to remove a medical sharp from a holder using induction heating. In particular, but not by way of limitation, the invention relates to an electrical control circuit for use with such an apparatus: the device is used to remove a metal pen needle cannula from a plastic pen needle hub by heating the cannula using induction heating and melting the adhesive or plastic securing the cannula to the plastic pen needle hub, and to an induction heating coil for use in such an electrical circuit. The control circuitry and means may also be used to remove a metal injector needle from a plastic needle hub or plastic injector barrel, a metal lancet from a plastic lancet holder, or a metal introducer needle from a plastic needle hub in a catheter assembly.

Background

After a metal sharps (such as an injection pen needle, syringe needle, hypodermic needle, lancet, or catheter introducer needle) has been used, it is desirable for several reasons to remove the sharps and store them in a safe container. For example, medical sharps are often dull after a single use, so subsequent use may cause discomfort to the patient. Additionally, multiple uses of a medical sharp may also reduce the strength of the sharp, which may cause potential breakage. Further, the reuse of medical sharps increases health concerns and health risks for the patient. Moreover, exposed medical sharps can pose health risks to patients, caregivers, and waste management workers.

Sharps containers (known in the art) for storing used needles comprise an inner cartridge member and an outer housing member. The cartridge and the housing each have an aperture sized to receive a hypodermic needle. The cartridge and the housing are hingedly connected to each other such that in the open position the aperture of the cartridge overlaps the aperture of the housing and a needle can be inserted through the two apertures to project into the cartridge. After the needle has been inserted into the aperture, the cartridge and the housing are moved relative to each other (e.g., in a scissor-type motion) such that the needle is sheared off. After being cut off, the needles fall into a magazine for storage and subsequent handling. Traditionally, sharps containers have been large red boxes, and insertion of medical sharps has been relatively easy, but removal of medical sharps therefrom has been apparently difficult.

U.S. patent No. 6,545,242 to Butler discloses a device that heats at least a portion of a needle to about 1750 ℃ after insertion of the portion of the needle and then shears the needle, leaving a portion in the needle holder or hub. Similarly, U.S. patent No. 5,545,869 to Piva discloses a device that melts a portion of the blade or needle and severs the remainder of the blade or needle, leaving a portion of the blade or needle in the needle/blade holder or needle hub. Additionally, U.S. patent No. 4,867,309 to german discloses a device that holds the needle and its holder or needle hub by a needle shaft so that the user can twist off the needle hub from the syringe or pull the needle hub off with the hub mounted on the syringe by a friction fit.

However, for each of these devices, a portion of the needle is retained in the needle holder. Thus, the possibility of needle stick injury may still exist. Additionally, the needle holder must be disposed of as medical waste and cannot be reused. Accordingly, an improved medical needle removal device that completely removes the needle is desired. Storage of the removed needles is also required.

Disclosure of Invention

According to one aspect of the invention, induction heating is used to separate a metallic medical sharp from its holder by applying a high frequency oscillating magnetic field that induces eddy currents in the sharp and resistive heating. The use of induction heating is advantageous because it does not require direct contact between the electrical circuit and the sharps or sharps holders, and the heating can also act to sterilize the sharps and thus make them less dangerous while separating them from their holders.

Separation of the sharps from the holder of the sharps may be accomplished in a number of ways, such as by melting all or part of the sharps, by locally heating the sharps so that it can be more easily severed or broken, by using a heated sharps to soften or melt the adhesive attaching the sharps to the holder of the sharps, or by using a heated sharps to soften or melt the abutting plastic material of the holder itself. These methods may be used alone or in combination with each other, and may also be used in combination with mechanical separation methods.

One challenge with using induction heating to separate a metallic medical sharp from its holder is the difficulty in concentrating sufficient Radio Frequency (RF) energy in a small metal body, such as a pen needle cannula, to produce the desired softening or melting temperature in a reasonably short period of time. Long power-on times are undesirable not only because they are inconvenient for the user, but also because they can cause overheating of the induction coil.

Another challenge is that while induction heating can operate most efficiently at close distances, certain types of sharps holders (such as pen needle hubs) are physically large relative to the metal sharps themselves and physically prevent the induction coil from being positioned close enough to the sharps for efficient energy transfer.

The oscillation frequency and/or amplitude may be increased to deliver more rf energy to the metal sharps in a given period of time, but the use of high frequencies and/or oscillations may cause undesirable rf radiation and may also require regulatory approval in some cases.

According to aspects of the present invention, these challenges are addressed in a variety of ways. In one aspect, a specially shaped induction coil is used to maximize the efficiency of the rf energy transfer to the metal sharps. The coil has a stepped shape defined by two axially spaced portions having different diameters and is useful for concentrating radio frequency energy in a metallic pen needle cannula mounted in a hub having a similar stepped shape.

Another aspect of the invention is the use of oscillation frequencies in the unlicensed industrial, scientific and medical (ISM) bands that allow efficient energy transfer without introducing regulatory requirements or requiring the design of a needle removal device to block all undesirable radio frequency radiation at these frequencies.

Yet another aspect of the present invention is to take advantage of the radio frequency "skin effect", which is the tendency of Alternating Current (AC), eddy currents induced by the induction coil in this example, to concentrate near the surface of the conductor in which the current flows. This effect becomes more pronounced at higher frequencies.

Since many types of medical sharps are designed such that their outer surfaces are mounted or incorporated into a plastic holder, the skin effect is advantageous in efficiently directing rf energy to specific portions of a metal sharps that require heating in order to release the sharps from its holder (i.e., the metal/plastic interface).

Drawings

Further aspects and advantages of embodiments of the present invention will be more readily understood from the following detailed description when considered in connection with the accompanying drawings, wherein:

figures 1 and 2 are perspective and cross-sectional views of a metal sharps removal and storage device according to an embodiment of the present invention;

fig. 3 and 4 are perspective and sectional views illustrating the operation of the exemplary device of fig. 1 and 2;

FIGS. 5 and 6 (including FIGS. 6A and 6B) are block and schematic diagrams of a first embodiment of an electrical control circuit for the exemplary device of FIGS. 1 and 2;

FIGS. 7 and 8 (including FIGS. 8A and 8B) are a block diagram and schematic diagram of a second embodiment of an electrical control circuit for the exemplary device of FIGS. 1 and 2;

FIG. 9 is a flow chart illustrating operation of the electrical control circuit of FIGS. 7 and 8 (including FIGS. 8A and 8B); and

fig. 10A and 10B show two possible shapes of magnetic induction coils used in the exemplary arrangement of fig. 1 and 2.

In these figures, like parts and components are denoted by like reference numerals.

Detailed Description

Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout the drawings. The embodiments described herein are illustrative of, but not limiting to, the invention by reference to the figures.

It is to be understood by those skilled in the art that the present invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. Embodiments herein are capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the elements listed thereafter and equivalents thereof as well as additional elements. Unless limited otherwise, the terms "connected," "coupled," and "mounted," and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms "connected" and "coupled" and variations thereof are not restricted to physical or mechanical connections or couplings. Further, terms such as "upward," "downward," "bottom," and "top" are relative and are used to aid in the illustration, but are not limiting.

Fig. 1 is a perspective view of an exemplary medical sharp removal and storage device 100, and fig. 2 is a cross-sectional view of the device 100, according to an embodiment of the present invention. The mechanical construction and operation of the device 100 is described in more detail in U.S. provisional patent application No. 62/529,926, summarized below and filed on 7/7 of 2017, which is incorporated herein by reference in its entirety.

The exemplary device 100 is adapted for use with disposable pen needles of the type commonly used with reusable pen injectors, but may also be used with other types of medical sharps. As shown, the apparatus 100 includes a body 102 and a heating unit 104. According to one embodiment, the heating unit 104 includes an energy source 106 (such as a battery 106 or the like), an induction coil 108, and a controller 110 electrically connectable to the energy source 106 and the induction coil 108. The controller may comprise a printed circuit board and may have circuit board components such as memory chips and a microprocessor. The apparatus 100 further comprises: a receiving unit 114 fixedly provided in the main body 102; a collet 122; sharps receiving container or chamber 124; first and second bias units 130 and 132; a door member 134, and a slider or user interface 136. In one embodiment, the sharps receiving container 124 can be removed from the body 102.

Fig. 3 and 4 illustrate the operation of medical sharps removal and storage device 100. In fig. 3, a user inserts a pen needle 140 connected to a pen injector 138 into the receiving portion 116 of the receiving unit 114. The pen needle 140 includes a plastic needle hub 142 and a medical sharp or needle cannula 144 made of metal, such as stainless steel. The splines of the pen needle engage the internal splines 120 of the receiving portion 116 to resist rotation of the pen needle 140 so that a user may unscrew the pen injector 138 from the pen needle 140 and remove the pen injector 138, leaving the pen needle 140 in the receiving portion 116 of the receiving unit 114.

When a user inserts the pen needle 140 into the receiving unit 114, the receiving portion 116 of the receiving unit 114 receives the needle mount 142 and the collet 122 receives the needle 144. When a user inserts the pen needle 140 into the receiving unit 114, the opened collet 122 receives the needle 144. After the user inserts the pen needle 140 into the receiving unit 114, the user closes the door member 134 by sliding the door member 134 forward relative to the main body 102. The closed gate member 134 helps to retain the pen needle 140 in the receiving unit 114 and detects the closed position of the gate member 134 to enable the controller 110 to energize the induction coil 108. For example, there may be a physical or optical sensor 182 connected to the controller 110 that is triggered when the door member 134 reaches the closed position after a predetermined displacement relative to the body 102. Alternatively, the door member 134 may have electrical contacts that complete a portion of the circuit to between the controller 110 and the induction coil 108. Other methods of enabling the controller 110 to energize the induction coil 108 may be utilized without departing from the scope of the invention. In addition to these features, the lower surface of the door member 134 is provided with an electrically conductive lining 135, preferably in the form of a metal foil or strip, which is connected to ground or a reference potential of the controller. This provides a shielding function, thereby reducing undesirable radio frequency emissions from the induction coil when the device is in operation.

After the user closes the door member 134, the user slides the slider or user interface 136 downward in a first direction (as shown by the arrow in fig. 4). While the user interface 136 is shown as a slider 136, those skilled in the art will appreciate that other user interfaces, such as a release button, may be utilized without departing from the scope of the present invention.

As shown in fig. 2 and 4, the second biasing unit or spring 132 is disposed on top of the lower flange of the collet 122 and the first biasing unit or spring 130 is disposed below the flange. Before the collet 122 moves, the first spring 130 biases the collet 122 toward the receiving unit 114. In the initial state shown in fig. 4, the second spring 132 also biases the collet 122 away from the receiving unit 114. In this initial state, neither the first spring 130 nor the second spring 132 biases the collet 122. It will be appreciated by those skilled in the art that by appropriately sizing the first and second biasing units 130 and 132, a desired force profile can be provided for the force exerted by the user on the slide 136 in order to operate the device 100.

A user interface or slider 136 is coupled to the collet 122. In one embodiment, the user interface or slide 136 is coupled directly to the collet 122. In another embodiment, another element (such as a second biasing unit or spring 132) is disposed between the user interface or slide 136 and the collet 122 and translates movement of the slide 136 into movement of the collet 122.

Moving the slider 136 a predetermined distance causes the collet 122 to grip the needle 144 and also activates the heating unit. According to one embodiment, the device 100 includes a mechanical or optical sensor 184 coupled to the controller 110 to determine when a predetermined movement of the slider or user interface 136 occurs to signal the controller 110 to complete the circuit and supply high frequency current to the induction coil 108. Alternatively, the slider or user interface 136 may have electrical contacts that complete a circuit from the energy source 106 to the induction coil 108, enabling the controller 110 to control the supply of energy to the induction coil 108.

Supplying energy to the induction coil 108 generates a strong, oscillating magnetic field in the middle of the induction coil 108. Because the metal medical sharp (i.e., the stainless pen needle cannula 144) is present within the coil 108, the oscillating magnetic field induces an eddy current in the metal medical sharp, which in turn causes resistive heating of the sharp. The heating softens and weakens the adhesive and/or plastic that connects the medical sharp 144 with the holder 142 (in this example, the plastic pen needle hub 142). A preferred configuration of the induction coil 108 is best seen in fig. 4, particularly including a configuration of a larger diameter upper coil portion 160 axially spaced from a smaller diameter lower coil portion 162. This stepped coil shape is similar to the stepped distal configuration of typical pen needles and enables the radio frequency energy generated by the coil to be applied as close as possible to the adhesive and/or plastic material at the interface between the metal needle cannula 144 and the plastic hub 142.

As the collet 122 is pushed downward by the force applied to the slider 136 by the user, once the inductive heating softens and weakens the connection between the needle 144 and the needle hub 142 sufficiently to allow the needle 144 to move relative to the needle hub 142, the collet 122, which is still gripping the needle 144, pulls the needle 144 downward and pulls the needle 144 away from the needle hub 142. As the collet 122 travels down the tapered section of the interior of the cylindrical portion 118 of the receiving unit 114, the radially inward force applied to the sharps receiving portion of the collet, and thus the collet's grip on the needle 144, is reduced. In other words, the tapered shape of the tapered section allows the collet 122 to expand as it travels in a first direction (i.e., downward in the drawing). The positioning of the tapered section is selected so as to allow the collet 122 to expand to release the needle 144 only after the needle has been pulled completely off the plastic needle mount 142.

According to one embodiment, a condition is achieved quite abruptly in which the induction heating softens and weakens the connection between the needle 144 and the needle hub 142 sufficiently to allow the needle 144 to move relative to the needle hub 142, and the collet 122 imparts momentum to the needle. Once the grip of the collet 122 is sufficiently reduced, the collet 122 releases the needle 144 and the momentum of the needle 144 carries the needle into the sharps receiving container 124.

Subsequently, the user releases the downward force applied to the slider 136 and the first spring 130 returns the collet 122 and thus the slider 136 to the initial position shown in fig. 2 and 4. Alternatively, the user may return the slider 136 (and thus the collet 122 due to the coupling of the collet to the slider) to the initial position shown in fig. 2 and 4.

According to one embodiment, the controller 110 supplies energy to the induction coil 108 for a predetermined amount of time. Alternatively, the controller may control the supply of energy to the induction coil 108 based on the position of the slider 136 or the collet 122 (e.g., via the previously described sensors or electrical contacts, or via a different sensor).

Once the needle 144 is separated from the needle hub 142, the user may open the door member 134 and remove the needle hub 142 from the device 100 for disposal or recycling, with the needle 144 safely disposed in the sharps receiving container or chamber 124. The heat (albeit brief) applied to the needle 144 prior to the needle 144 being separated from the needle hub 142 may have the effect of sterilizing the needle 144 and thus making it less dangerous during any subsequent operation or handling. The opening of the sharps receiving container 124 may be provided with a rubber septum-like barrier or a duckbill valve that opens through a wedge or cone when the container 124 is attached to the body 102 of the device 100, allowing the needle 144 to enter the container 124. When the container 124 is removed for disposal, the diaphragm or valve will spring closed so that the needle 144, and any other separate sharps in the container 124, are retained therein and cannot fall out.

In the illustrated example of fig. 1-4, the medical sharp is a metal pen needle cannula 144 and the holder is a plastic pen needle hub 142. Other medical sharps and holders may also be separated using the device 100. Generally, any medical device having a potentially hazardous metal sharps member that needs to be separated from a plastic holder and contained for disposal may be accommodated by the device 100. For example, a metal lancet, stylet, or trocar can be detached from its handle, a metal needle cannula can be detached from a stake injector or from a hub or holder mounted to the injector, and a metal catheter introducer needle can be detached from its hub or holder. A cutout 146 (best seen in fig. 1) in door member 134 accommodates a lancet, stylet, or trocar handle, syringe, or catheter introducer, while device 100 serves to separate the medical sharp from its holder and still allow door member 134 to close. Similarly, the shape of the receiving unit 114 may be altered to accommodate these different types of medical devices by providing a snug fit between the receiving unit 114 and a plastic holder or handle to which a metal sharps is attached.

The main body 102, the receiving unit 114, the collet 122, the door member 134, the slider 136, and the sharps receiving container 124 may be made of plastic, such as polypropylene (PP), polyethylene (PE), polycarbonate (PC), acrylonitrile Butadiene Styrene (ABS), or Polyetheretherketone (PEEK). The different components may be made of different plastics. Preferably, the collet 122 is ceramic or made of metal (e.g., aluminum).

Embodiments of the invention (with induction coils) are particularly useful in situations where: in this case, it is difficult to directly access the multiple contact points on the medical sharp, thus making the conductive heating mechanism less implementable.

Embodiments of the present invention provide a portable personal sharps container and removal device that allows for safe containment and disposal of contaminated sharps and that may improve needle handling compliance for users of needles.

Embodiments of the invention may operate by: removing only the metal sharps part of the injection device (e.g. but not limited to a pen needle or syringe) and storing the metal sharps part inside the device while allowing the user to dispose of the plastic non-sharps member as ordinary waste or recyclable component. Embodiments of the present invention may achieve this effect by inductively generating a strong high temperature region in conjunction with a "pull-out" mechanism, for example, near an adhesive bead that adheres a medical sharp to a holder.

In embodiments of the invention, heating may be achieved by an induction heating structure. With such a mechanism, it is not necessary to directly contact the heating mechanism with the needle. However, heating may also be achieved in other ways, such as by directly contacting a heating element of the medical sharp, or by contacting the medical sharp to complete an electrical circuit to pass current through the medical sharp. See, for example, commonly assigned U.S. patent nos. 8,829,394, 9,579,469, and 9,802,006, the entire contents of which are expressly incorporated herein by reference.

In certain embodiments of the present invention, the device 100 has a durable component as well as a disposable component. The durable component utilizes a power source, such as a battery (rechargeable or otherwise). An indicator may be incorporated into the device that alerts the user when the cannula holding compartment has reached a certain volume. Similar features may be used to manage power requirements such as battery replacement or recharging. A disposable member (chamber or sharps receiving portion) may be utilized until a sufficient number of needles have been introduced into the chamber, after which it may be removed and properly disposed of. Appropriate processing may include various options, for example, the disposable components may be mailed to the manufacturer or a separate waste management entity, or the disposable components may be discarded in an appropriate medical waste container. Preferably, replacement of the disposable component is available to continue to use the durable component for subsequent medical sharps removal.

Fig. 5 is a block diagram of a first exemplary electrical control circuit for the apparatus 100 of fig. 1 and 2. Heating unit 104 may be configured as a power subsystem 112 that includes an energy source 106 and a DC chopper type boost converter circuit 113. According to one embodiment, the boost converter circuit 113 and the induction heating resonant circuit 115 are part of the controller 110. In one embodiment, the energy source 106 comprises one or more batteries, such as two 3.7 volt lithium ion batteries connected in series. The boost converter circuit 113 converts the 7.4 volt DC output of two series-connected lithium ion batteries to a 28 volt DC output. Those skilled in the art to which the invention pertains will appreciate that other battery configurations or other types of batteries may be utilized without departing from the scope of the invention. According to one embodiment, the energy source 106 can be removed from the body 102 and replaceable. Although not shown in fig. 5, the power supply subsystem 112 may be controlled by one or both of the previously mentioned sensors 182, 184, or in some other manner, such that it applies power to the inductive heating resonant circuit 115 only when a user has properly inserted a medical sharp and has activated the collet 122.

Fig. 6 (including fig. 6A and 6B) is a detailed schematic diagram of the electrical control circuit of fig. 5. Voltage reference circuit 170 utilizes zener diode U2 to generate a low voltage reference that controls the frequency of the inductive oscillator (oscillating circuit). The voltage reference is provided as an input to an oscillator drive circuit 172, which utilizes an operational amplifier (op amp) U1 in conjunction with the illustrated trimming resistors and capacitors to produce the desired oscillation frequency of 27 MHz. The output of operational amplifier U2 is applied as an input to a drive (amplifier) circuit 174, which uses bipolar transistors Q1 and Q2 to provide the desired output power (approximately 60 watts) to a coupling transformer 176. The coupling transformer 176 provides voltage boosting and impedance matching to the magnetic induction heating coil 108 of the needle removal device 100. The power supply 178 filters and moderates the 28 volt DC output from the battery 106 and the boost converter circuit 113 that make up the 28 volt power subsystem 112.

It should be noted that frequencies other than 27MHz may be used, with corresponding changes to the drive circuitry and induction coil geometry. For example, 43MHz is another unlicensed frequency suitable for use in the present invention. Typically, frequencies in the unlicensed ISM band are preferred, but this is not essential.

Fig. 7 is a block diagram of a second exemplary electrical control circuit for the apparatus of fig. 1 and 2. In this circuit, a microcontroller unit (MCU) 180 is used to control the functions of the circuit, including changing the oscillation frequency of the resonant circuit and detecting the state of the various sensors and detectors 182-188. Fig. 8 (including fig. 8A, 8B) is a detailed schematic diagram of the present embodiment in which the voltage reference circuit 170 is deleted and replaced with a digital-to-analog conversion (DAC) output from the MCU 180. The voltage level on line 181 controls the oscillation frequency of magnetic induction coil 108 and thus the amount of rf power applied to the sharps (which are being separated from its holder). The MCU receives inputs from a sensor 182 for detecting the position of the door member 134, a sensor 184 for detecting the position of the slider 136, a needle insertion detector 186, and a needle size detector 188. In certain embodiments, sensors 186 and 188 may be combined into a single sensor. A voltage regulator 190 coupled to the power subsystem 112 provides the required DC supply voltage to the MCU 180.

Fig. 9 is a flow chart describing the operation of the apparatus 100 of fig. 1 and 2 when provided with the MCU-based control circuit of fig. 7 and 8. When waking from a sleep state at the indication of numeral 200, the MCU checks at the indication of numeral 202 to determine whether a needle has been inserted by detecting the state of the needle insertion detector 186, which may take the form of an electronic (e.g., inductive or capacitive) sensor, a mechanical sensor, or an optical sensor. If a needle has been inserted, the MCU then verifies at numeral 204 that the safety interlock device 182 for the door member 134 has been activated. After the collet 122 has been locked onto the pen needle cannula 144 as indicated by numeral 206, the MCU checks the cannula size (gauge) as indicated by numeral 208 to determine if it is large or small. This is done using a needle size detector 188, which needle size detector 188 may also take the form of an electronic (e.g., inductive or capacitive) sensor, a mechanical sensor, or an optical sensor. As already mentioned previously, the sensors 186 and 188 may be combined into a single sensor. If the needle is determined to have a small gauge, the MCU applies a higher boost converter frequency and voltage for a shorter period of time (e.g., 2 seconds) at numeral 210, whereas if the needle is determined to have a large gauge, the MCU applies a lower boost converter frequency and voltage for a longer period of time (e.g., 3 seconds) at numeral 212. Since the pins act as resonant antennas, these parameters produce optimal resonance and inductive coupling for the respective pin sizes. In both cases, if the current consumption is determined to be excessive (this determination may be made via a temperature sensor or by direct measurement of the current consumption), the MCU has the ability to turn the oscillation off early as indicated by the numerals 214, 216. After a predetermined duty cycle (on time), the output to the induction coil 108 is terminated by the MCU as indicated by numeral 218, the cannula 144 is removed as indicated by numeral 220, the collet 122 mechanism is released as indicated by numeral 222, an audible or visible completion signal is generated and the power to the control circuit is turned off as indicated by numeral 224, and the processor re-enters the sleep state as indicated by numeral 226.

Fig. 10A is a detailed view of the induction coil 108 showing a larger diameter upper coil portion 160 and an axially spaced, smaller diameter lower coil portion 162, which together provide a stepped shape to the coil in side view. While this coil shape is preferred, other coil geometries are possible. For example, a conical geometry is shown in fig. 10B, where the induction coil 108' narrows more gradually in the axial direction from the top 228 to the bottom 230.

While only a few embodiments of the present invention have been shown and described, the present invention is not limited to the described embodiments. Rather, it will be appreciated by those skilled in the art that changes could be made in these embodiments without departing from the principles and spirit of the invention. Any of the embodiments and/or elements disclosed herein may be combined with each other to form various additional embodiments not specifically disclosed, so long as they are not mutually inconsistent. It is particularly noted that various technical aspects of the individual elements of the various exemplary embodiments that have been described above may be readily combined in many other ways by a person skilled in the art to which the invention pertains, all of which are deemed to be within the scope of the invention, which is defined by the appended claims and their equivalents.

Claims (26)

1. An apparatus for removing a medical sharp from a holder, comprising:

a magnetic induction coil; and

a control circuit for energizing the magnetic induction coil;

characterized in that the magnetic induction coil has a stepped shape defined by two axially spaced portions having different diameters, or a conical shape defined by a diameter that gradually changes in an axial direction, the magnetic induction coil having a shape that is disposed around the holder and around a portion of the medical sharp received in the holder.

2. The apparatus of claim 1 wherein the medical sharp comprises a metal pen needle cannula and the holder comprises a plastic pen needle hub.

3. The apparatus of claim 1, wherein the control circuit energizes the magnetic induction coil at a frequency of approximately 27MHz or approximately 43MHz.

4. The apparatus of claim 1, wherein the control circuit comprises a microcontroller unit.

5. The apparatus of claim 1, wherein a shape of the magnetic induction coil corresponds to a shape of the holder.

6. An apparatus for removing a medical sharp from a holder, comprising:

a magnetic induction coil configured to surround the holder and surround a portion of the medical sharp received in the holder; and

a control circuit for energizing the magnetic induction coil;

wherein the control circuit energizes the magnetic induction coil at a frequency of approximately 27MHz or approximately 43MHz.

7. The apparatus of claim 6 wherein the medical sharp comprises a metal pen needle cannula and the holder comprises a plastic pen needle hub.

8. The apparatus of claim 6, wherein the control circuit comprises a microcontroller unit.

9. An apparatus for removing a medical sharp from a holder, comprising:

a magnetic induction coil configured to surround the holder and to surround a portion of the medical sharp received in the holder; and

a control circuit for energizing the magnetic induction coil;

wherein said control circuit energizes said magnetic induction coil at a voltage and/or frequency that is at least partially dependent on a size or gauge of said medical sharp.

10. The apparatus of claim 9 wherein the medical sharp comprises a metal pen needle cannula and the holder comprises a plastic pen needle hub.

11. The apparatus of claim 9, wherein the control circuit comprises a microcontroller unit.

12. An apparatus for removing a medical sharp from a holder, the apparatus comprising:

a magnetic induction coil configured to surround the holder and surround the medical sharp received in the holder;

a control circuit for energizing the magnetic induction coil;

a housing for enclosing the magnetic induction coil and the control circuitry, the housing configured for receiving the medical sharp and the holder;

a movable door for providing access to the housing; and

a sensor coupled to the control circuit for detecting an open state or a closed state of the movable door.

13. The apparatus according to claim 12 wherein the medical sharp comprises a metal pen needle cannula and the holder comprises a plastic pen needle hub.

14. The apparatus of claim 12, wherein the control circuit energizes the magnetic induction coil at a frequency of approximately 27MHz or approximately 43MHz.

15. The apparatus of claim 12, wherein the control circuit comprises a microcontroller unit.

16. The apparatus of claim 12 further comprising a movable jaw for holding the medical sharp when in the first position and movable to the second position to separate the medical sharp from the holder.

17. An apparatus for removing a medical sharp from a holder, the apparatus comprising:

a magnetic induction coil;

a control circuit for energizing the magnetic induction coil at a radio frequency;

a housing for enclosing the magnetic induction coil and the control circuitry, wherein the magnetic induction coil surrounds at least a portion of the holder and surrounds a portion of the medical sharp received in the holder;

a movable door for providing access to the housing; and

a metal shield on the movable door for reducing radio frequency radiation from the housing.

18. The apparatus of claim 17 wherein said medical sharp comprises a metal pen needle cannula and said holder comprises a plastic pen needle hub.

19. The apparatus of claim 17, wherein the radio frequency is approximately 27MHz or approximately 43MHz.

20. The apparatus of claim 17, wherein the control circuit comprises a microcontroller unit.

21. The apparatus of claim 17 further comprising a collet configured to hold the medical sharp when the medical sharp and the holder are inserted into the apparatus and in a first position, and wherein the collet is movable to a second position to separate the medical sharp from the holder upon heating the medical sharp to a temperature at which the medical sharp can be released from the holder.

22. The apparatus of claim 21 further comprising a cylindrical portion for receiving the collet in the first position, the collet holding the medical sharp and being movable to a second position, the medical sharp being spaced from the collet in the second position.

23. The apparatus of claim 22, further comprising a user interface for moving the collet from the first position to the second position.

24. The apparatus of claim 23, further comprising a first spring extending between the collet and the user interface, wherein the first spring is in a loaded state when the user interface moves from the first position to the second position.

25. The apparatus of claim 24, further comprising a second spring biasing the collet toward the cylindrical portion to the first position.

26. The apparatus of claim 25 wherein the user interface in the second position compresses the first spring to exert a force on the collet, wherein the medical sharp is heated to a temperature sufficient to separate the medical sharp from the holder, and wherein the first spring in a loaded state has a biasing force to move the collet to the second position against the action of the second spring, thereby separating the medical sharp from the holder.

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