Patent Application
20060224123
The present invention relates to devices for delivering, administering or dispensing substances, and to methods of making and using them. More particularly, it relates to a device for administering a fluid product, comprising measuring means for measuring, without contact, a position of elements of the administering device which can be moved with respect to each other, and to a method for measuring, without contact, their position with respect to each other. More particularly, in one embodiment, the present invention relates to measuring the setting of an administering or dosing device or mechanism of an injection apparatus.
Devices such as those that the present invention relates to are used in many areas, including in the medical field for administering or injecting a medical or pharmaceutical product. Injection apparatus, such as for instance injection pens, may be used for dispensing insulin, hormone preparations and the like. An injection apparatus comprises various mechanical means, such as an administering or dosing means, to be able to exactly dispense a particular product dosage from the apparatus. In order to monitor the administering process and its accuracy, it is usual to arrange sensors or probes within the apparatus, which detect the movement of various elements of the mechanical means. From this, the setting of the mechanical means is ascertained, for example by means of a microprocessor, and can be indicated on or by the injection apparatus by a mechanical or electronic display.
Since mechanical scanning is susceptible to contamination, moisture and wear and exhibits large tolerances between the individual elements, which restricts the accuracy in measuring the setting of an injection apparatus, non-contact methods for determining the setting of such an apparatus have been developed. To this end, a number of sensors or measuring devices may be arranged at various points on the apparatus.
WO 02/064196 A1 discloses an injection apparatus controlled by a closed switch unit comprising integrated sensors which monitor selected parameters of the apparatus. The closed switch unit is fixed within the injection apparatus. At least two pairs of integrated Hall elements are used as the sensors. The Hall elements co-operate with a magnetised ring which alternately exhibits north and south poles. The ring is arranged within a dosing means and is moved around the longitudinal axis of the injection apparatus in accordance with a rotational movement for setting a product dosage. In order to measure the volume of a dosage setting, it is necessary to determine the rotational movement of the magnetic ring relative to the closed switch unit. To this end, the Hall elements are arranged on a circular arc opposing the magnetic ring, in a defined arrangement with respect to each other and the magnetic ring. When movement is started, a start angle is defined and, on the basis of measuring the magnetic field during the movement of the magnetic ring relative to the Hall elements, an end angle is determined once the movement is terminated. The start and end angles and the measured magnetic field are compared with a stored table and a product dosage set is determined from the comparison.
EP 1095668 discloses an electronic administering pen for medical purposes which, in order to measure the setting of an administering means of the pen, measures the linear position of a helical rod of the administering mechanism or the rotational position of a setting button of a dosing means. An optical code converter comprising a code disc coupled to the rotational movement of the setting button is used. The rotational movement of the code disc is measured by an optical receiver. A microprocessor converts the number of rotations by the code disc into a dosage amount corresponding to the setting. Another sensor is provided between the windings of the helical rod of the administering means and registers the movement in the longitudinal direction along the longitudinal axis of the pen. The administered amount of a product is determined from the shift of the helical rod. The two sensors operate independently of each other and each determine only one movement direction of a mechanical means of the pen.
While such measuring means for measuring without contact can increase the accuracy in measuring a setting as compared to mechanical scanning, the arrangement of the individual parts of such measuring means within the apparatus is complex, such that manufacturing the apparatus is complicated and expensive. In addition, the circuitry and measuring methods of the aforementioned measuring means are susceptible to moisture, vibrations and other such effects. Accommodating the individual parts of the measuring means, such as the sensors and the counter pieces for the sensors, often requires structural changes in an administering device, making it unnecessarily large or even restricting the other mechanisms and/or functions of the device.
It is an object of the present invention to provide a device for administering a fluid product incorporating measuring means for measuring and/or assessing operational parameters of the device. It is another object of the present invention to provide measuring means for use with devices for administering, delivering, injecting or infusion a substance, and a method of making and using the measuring means. Another object of the present invention is to reduce the number of components needed to accomplish the aforementioned objects, and to enable only small movements of the elements of the device (e.g., operational, mechanical, functional structures or features of the device) to be measured or assessed exactly or as precisely as possible. It is another object of the present invention to provide a non-contact method for measuring the setting and/or performance of mechanical means of an administering device, said method enabling a movement and the position of selected elements of the apparatus to be easily determined and increasing the accuracy in measuring the setting and/or performance.
In one embodiment, the present invention comprises a device for administering a substance comprising a measuring mechanism for measuring and/or assessing, without contact, a position relative to at least two elements of the device, at least one of the elements moveable with respect to the other, the measuring mechanism comprising at least two optical sensors for sensing a relative movement between the elements, the relative movement providing a profile trajectory. The present invention encompasses a method for measuring, without contact, a relative position between elements or structures which can be moved relative to each other, wherein sensors sense and/or record a profile trajectory associated with the elements or structures when one element is moved relative to another element, the trajectory processed to determine the position.
The present invention involves administering, delivering or dispensing devices such as injection devices. Typically, injection devices comprise various mechanical means such as an administering or dosing means constructed from a number of elements at least some of which are moved relative to each other within the apparatus when the apparatus is operated. For example, to administer a product from the apparatus, a sliding element such as a toothed rod is moved along the longitudinal axis of the apparatus relative to a product container, an apparatus casing or other guiding elements of the administering means. A dosing means for setting a dosage volume to be administered may include a rotational element which is rotated relative to the casing or a threaded rod. In accordance with the present invention, in addition to these and/or other operational or functional structures or mechanisms, the injection apparatus comprises a measuring means which measures the setting of a mechanism of the apparatus and, therefore, of the setting or state of the injection apparatus, by determining the movement of elements relative to each other.
In accordance with the present invention, in one embodiment, the measuring means includes at least two optical sensors. The optical sensors can be provided by suitable optoelectronic units using which optical radiation can be generated, detected, transmitted, converted into electrical signals and processed. An optical sensor can therefore consist for example of radiation emitters, radiation receivers or optocouplers. In some preferred embodiments, the optical sensors may comprise a laser detector, reflex detector or light barrier.
In some embodiments, the at least two optical sensors are arranged, fixed with respect to each other, on at least a first element of an injection apparatus. The two sensors are therefore in a fixed spatial relationship to each other. It is possible for the sensors to be fixed to different elements of the apparatus, which for their part are fixed with respect to each other. The at least two optical sensors are arranged on the first element such that they oppose a second element of the injection apparatus. It is not necessary to pay any particular consideration to the distance between a first element, i.e., a sensor, and a second element. Care should merely be taken that no other elements lie between the first element and the second element, which could disrupt optical measuring.
The measuring means or measuring means component on the second element also exhibits a surface profile which provides a different predetermined profile trajectory for each of the sensors when the first element and the second element are moved relative to each other. The surface structure of the second element therefore exhibits a characteristic formation or an additional agent is provided which gives the second element a characteristic surface structure. When the first element is moved relative to the second element, such as when a sliding element of a dosing or administering means is slid or a rotational element rotated, relative to the first element comprising the sensors, the surface profile of the second element is guided past the sensors and the sensors measure the profile trajectory of the surface profile, wherein the surface profile is formed such that the sensors each register one predetermined profile trajectory and the profile trajectory measured by one sensor during movement differs from the profile trajectory measured by another sensor during this movement.
The surface profile preferably comprises a profile area or of a number of profile areas exhibiting a periodic surface structure running in the movement direction of the elements. In a surface profile comprising only one profile area of a periodic surface structure, the sensors are offset in the movement direction and arranged at different points of the period of the surface structure. The sensors may be, for example, arranged adjacently in the movement direction, such that one sensor opposes a period maximum and one sensor for example opposes a period cusp point of the surface structure. In some preferred embodiments, however, the sensors are not both arranged opposite an extreme point of the period such as a maximum or minimum.
If the surface profile exhibits a number of profile areas comprising a periodic surface structure, the sensors can be arranged adjacently, transverse with respect to the movement direction, each over one profile area. A surface profile may comprise two homogeneous profile areas offset with respect to each other in the movement direction. Two sensors arranged adjacently, transverse with respect to the movement direction, therefore detect a particular period point such as for instance a period maximum of a profile area at different times when the second element is moved relative to the first element.
The periodic surface structure of a profile area can, for example, be created by at least two periodically alternating height levels. When the elements are moved relative to each other, the distance between a sensor and the surface of the second element therefore changes periodically in accordance with the alternating height levels. A simple cam shaft or cam disc may used to this end. A profile area of a surface profile of the second element could also be formed by periodically arranged holes or cavities on the surface. When the elements are moved relative to each other, the light beam of a radiation emitter of an optical sensor then either passes through the holes or cavities or can be reflected by the surface. The holes or cavities on the surface profile of the second element may, for example, be formed by one or more perforated or slit discs fixed on the second element.
It is also possible to form the profile areas of the surface profile using periodically alternating light and dark fields. This could, for example, be provided by coloring the second element or by an additional ring or strip on the second element. A light beam of a radiation emitter is absorbed and/or reflected differently by the light and dark fields. On the second element, the periodic surface structure of a profile area extends in the circumferential direction or in the longitudinal direction of a longitudinal axis of the injection apparatus. In some preferred embodiments, the surface profile of the second element comprises profile areas whose periodic surface structure extends both in the longitudinal direction and the circumferential direction of the injection apparatus.
A particular surface profile may be selected in view of the type of an optical sensor used. If a laser detector is used, the optical sensor measures the predetermined profile trajectory when the elements are moved relative to each other, for example by scanning height levels which periodically change during movement or the changing distance between the sensor and the surface of the second element. If a reflex detector is used as the optical sensor, the intensity of the light reflected by the surface profile is generally measured. The intensity changes as the elements are moved relative to each other, for example by a periodically changing distance between the surface of the second element and the sensor due to changing height levels of a profile area.
It is also possible to generate a change in intensity at the sensor using different angular positions of the surface of the second element with respect to the sensor, such that a light beam of the detector incident onto the surface is reflected in different directions in accordance with the predetermined surface profile. A profile area can then be formed by various faces running or extending obliquely with respect to the incident direction of the light. The faces of the surface profile are then also arranged obliquely with respect to the longitudinal axis of the injection apparatus.
It is also possible, when using a reflex detector, to generate a predetermined profile trajectory by the light beam being reflected more or less by light and dark fields of the surface profile. If a light barrier is used, the predetermined profile trajectory can be generated by periodically arranging holes or cavities, for example on a perforated or slit disc.
When configuring the profile areas of the surface profile, it is also possible to provide—in additional to the periodic surface structure—a reference point which is distinguished from the periodic surface structure. This can be accomplished, for examples, by a providing a particularly high or low height level, by providing a particularly large or narrow hole on a perforated disc, or by a face having an angular position with respect to the sensor which is different to the other faces.
The profile area recorded by each sensor is transmitted as a measurement signal to a microprocessor in the injection apparatus, which processes the individual measurement signals and ascertains from them the position of the first element and the second element with respect to each other. A dosage setting or an administered product amount can then be calculated from this newly ascertained position and the initial position before the elements were moved with respect to each other or another reference position. To this end, the initial position before movement is preferably stored in a memory and the newly calculated position is also stored in the memory as a new initial position. The ascertained data of the dosage setting or the product amount can be read from an optical display.
In one preferred embodiment of an injection apparatus in accordance with the invention, two optical sensors are arranged on a first element which is fixed relative to a casing of the injection apparatus. The second element is formed by a sliding element which can be shifted in the longitudinal direction of a longitudinal axis of the apparatus, relative to the casing, or by a rotational element which can be rotated around the longitudinal axis of the apparatus, relative to the casing, as described above for an administering or dosing means.
In some embodiments, when determining the setting of the first element and the second element with respect to each other, it is also possible to measure discrete setting positions. A discrete setting position may, for example, correspond to a period or half a period of the periodic surface structure of a profile area. It is then particularly advantageous if, in accordance with the discrete setting positions for a movement direction on a second element, a surface profile which is suitable for measuring another movement direction is provided. If, for example, a number of discrete setting positions are determined on the circumference of a rotational element, it is possible to provide the surface profile, in accordance with these discrete rotational positions on a sliding element, using a number of homogeneous profile area combinations having a periodic surface structure in the longitudinal direction of the apparatus. A surface profile area is then assigned to each discrete rotational position, said surface profile area enabling a movement in the longitudinal direction of the sliding element to be measured, for example after the rotational movement of the rotational element has been measured. It is then advantageous if the two sensors oppose both the rotational element and the sliding element and therefore also the corresponding profile area of the rotational element and of the sliding element. The rotational element and the sliding element may be formed by a single element which can be both rotated and shifted relative to the first element. This can be provided by a sleeve of the apparatus which is rotated around the longitudinal axis of the apparatus in order to set the dosage and is shifted relative to the first element in order to administer the product from the apparatus.
It is conceivable to provide, in addition to the two optical sensors, a third optical sensor which serves as a monitor switch for the two optical sensors. A third optical sensor can improve the reliability of the injection apparatus. In one embodiment, the surface profile for the third optical sensor can be formed such that it registers a change in surface every time either the first sensor or the second sensor records a change. If the third sensor registers a change in surface and neither of the two other sensors records a change, then the injection apparatus is operating incorrectly.
Using optical sensors increases the design possibilities in the interior of an administering device, since the distance between an optical sensor and the surface profile necessary for measuring is very flexible. Optical sensors are typically small components or devices, such that the size of an administering device can be reduced. In most cases, the optical sensors are available as standard components, which makes the device cost-effective to manufacture. By combining at least two optical sensors and adapting the surface profile which co-operates with the sensors, it is possible to accurately and reliably determine the setting of two elements with respect to each other.
The present invention encompasses a method for measuring, without contact, a position between elements of a device for administering a fluid product, in particular an injection apparatus, wherein said elements can be moved relative to each other. In one embodiment, the method involves an apparatus comprising at least two optical sensors which are fixed with respect to each other and arranged on at least a first element and oppose a surface profile on a second element which can be moved with respect to the first element. Accordingly, an injection apparatus such as described above may be involved. In one embodiment, the method is used in an injection apparatus including an administering means comprising a sliding element which can be moved in the longitudinal direction of the longitudinal axis of the apparatus, and including a dosing means comprising a rotational element which can be rotated around the longitudinal axis. Furthermore, in one embodiment, an element which is fixed with respect to a casing of the injection apparatus, or the casing itself, is preferably used as the first element.
In accordance with the invention, each of the optical sensors is moved over the surface profile of the second element when the first element is moved relative to the second element, each sensing and/or recording a different predetermined profile trajectory. The profile trajectories recorded by each of the sensors are processed together, in order to determine the path distance travelled during movement. For a sliding element of an administering means, this path distance can correspond to the advance of a piston, which determines a product amount administered from the apparatus. For a rotational element of a dosing means, the path distance travelled corresponds to an angular distance using which the change in a dosage setting can be indicated. In principle, it is possible to determine a path distance travelled using only one sensor. By processing the different profile trajectories of various sensors, however, the path distance travelled can be determined reliably and substantially continuously in fine gradations, even when the periodicity of an individual surface area cannot allow measuring to be so finely gradated. In order to ascertain the position of the first element with respect to the second element, the profile trajectories recorded by the sensors are outputted as measurement signals to a suitable microprocessor or computer, and the path distance travelled is correlated with an initial position before the movement is started or with a reference position, as explained above.
A surface profile of the second element comprises one or more profile areas having a predetermined periodic surface structure, such as, for example, described above. In order to record a predetermined profile trajectory, the optical sensors are guided over a profile area of the surface profile when the elements are moved relative to each other. A light beam of an optical sensor is then differently affected in accordance with the periodic surface structure of the profile area, which creates the predetermined profile trajectory during movement. The optical sensors can record a different predetermined profile trajectory by being arranged over or operatively associated with the same profile area or over various profile areas, as described above. If the optical sensors are guided over the profile areas or the profile areas are moved past the optical sensors, a characteristic point of the periodic surface structure is recorded, offset in time, by the optical sensors. Such a characteristic point can be formed by the edge of changing height levels or by the start of a hole or cavity.
In may not be possible to form the periodic surface structure of a profile area of the surface profile as closely or finely as desired. The shortest possible path distance which may then be measured is therefore determined by the periodic surface structure. For a periodic surface structure consisting of two periodically alternating height levels, the minimum unit of distance which can be measured is, for example, given by the distance between two edges of the height level transitions. For a perforated disc, the minimum distance which can be measured is defined by the distance between the holes. In the method in accordance with the invention, different predetermined profile trajectories are recorded by the sensors when the elements are moved relative to each other, and processed together. This enables distances to also be determined which are shorter than the minimum path distance which can be measured by a sensor, since a characteristic point of a profile trajectory recorded by another sensor can lie within the minimum path distance which can be measured by a sensor.
It is advantageous to also be able to easily determine the movement direction of the elements with respect to each other by processing the different profile trajectories. If, for example, a surface profile consists of a first and second profile area arranged adjacently and exhibiting the same periodic surface structure in the form of periodically changing steps, and of two sensors which are adjacently arranged transverse with respect to the movement direction, each over a profile area, then the edge of a step of the profile areas is first registered by the one sensor or the other sensor, depending on the movement direction. The movement direction of the elements with respect to each other can easily be determined from such a characteristic relationship of the different profile trajectories measured by the sensors.
In one embodiment, the present invention comprises a device for administering a fluid product, such as for instance an injection apparatus, comprising a measuring means for measuring, without contact, a position between elements which can be moved with respect to each other, said measuring means including an optical sensor on a first element, said optical sensor facing a second element which can be moved with respect to the first element. The first element and the second element of the injection apparatus can be moved in the radial direction with respect to the longitudinal axis of the injection apparatus, such that the distance between the first element and the second element changes.
The optical sensor is in turn arranged on a first element which is fixed relative to a casing of the injection apparatus or is arranged on the casing itself. The second element can be a slider or a reset ring of a locking means of the injection apparatus, which in a first position unlocks the apparatus and in a second position, offset in the radial direction of the longitudinal axis with respect to the first position, locks the apparatus.
The optical sensor is therefore arranged generally opposite the second element, such that it can measure the changing distance between the first and the second element when the elements are moved relative to each other. When the elements are moved, a light beam of the optical sensor is differently deflected or reflected by a surface of the second element opposite the sensor, in accordance with changing distance, and this difference is registered by the sensor.
It is possible in principle for the element which can be moved radially with respect to the longitudinal axis to simultaneously also be able to be moved along the longitudinal axis or around the longitudinal axis. It is then advantageous if the surface opposite the first element exhibits a surface profile comprising one or more profile areas which are characteristic of various rotational or longitudinal positions. To this end, the surface profile can comprise various steps or a surface which extends obliquely with respect to the radial movement direction. In this way, the optical sensor can simultaneously determine a longitudinal position, a rotational position and a radial position.
The present invention enables the setting of an injection apparatus to be measured and/or assessed as optimally as possible by using optical sensors and formed surfaces which co-operate with the sensors. It is, of course, possible to combine different types and numbers of sensors and to measure the position of different pairs of first and second elements. The measurement signals of the various sensors or the ascertained settings of pairs of elements can then in turn be processed to help accurately monitor the injection apparatus. Advantageously, the sensors are arranged and the surface profiles formed such that a number of elements or movement directions can be measured using only a few sensors.
With regard to fastening, mounting, attaching or connecting the components of embodiments of the present invention, unless specifically described as otherwise, conventional fasteners such as screws, rivets, toggles, pins and the like may be used. Other fastening or attachment means appropriate for connecting components include friction fitting, adhesives, welding and soldering, the latter particularly with regard to electrical or processing components or systems. Any suitable electronic, electrical, communication, control or controller, computer or processing components may be used, including any suitable electrical components and circuitry, wires, wireless components, sensors, chips, boards, micro-processing or control system components, software, firmware, hardware, etc.
A beam or narrow plate 4 is fixed to the casing 1 which forms a part of the casing 1 and to which three optical sensors are attached in the form of laser detectors 5, 6 and 7. The laser detectors are attached adjacently in the longitudinal direction of the injection apparatus. A surface profile 8 comprising a first profile area A and a second profile area B is provided on the sleeve 3, opposite the sensors 5 and 6. The profile areas A and B exhibit a periodic surface structure in the form of two different alternating height levels. To this end, steps of equal length in the circumferential direction are arranged on a disc placed on the sleeve 3 and are repeated after a particular distance. The disc is coupled to the rotational movement of the sleeve 3, but remains at rest when the sleeve 3 is moved in the longitudinal direction. As may be gathered from
The measurement signals of the laser detectors 5, 6 and 7 are forwarded to a microprocessor 10 for processing, said microprocessor 10 ascertaining the position of the sleeve 3 relative to the casing 1 from the measured data and converting it into, for example, a dosage setting value or administering value. The ascertained values may be indicated or displayed, for example on a display 11 below a transparent area of the casing 1.
a and 3b show a detail from
a and 4b show a cross-section through the slider 12 of the locking means.
Comparable to
a and 7b show an area from
a shows an area of the injection apparatus comprising locking means. In this embodiment, the slider 12 comprises a protrusion 24 on its side opposite the light barrier 21, wherein in an unlocked position, said protrusion 24 engages between the prong arms of the light barrier 21, such that the radiation receiver does not register any light, as shown in
The invention has been explained in detail on the basis of the three exemplary embodiments. In principle, however, a multitude of different possible sensors and arrangements of sensors, including optical sensors, may be used relative to a selected surface profile without deviating from the concept of the invention. Thus, for example, it is possible to provide two co-operating optical sensors on opposite inner sides of a casing 1, or to combine different types of optical sensors. The described surface structures of the profile areas may also be combined. Thus, it is possible, when using reflex detectors, to additionally arrange light and dark fields on the oblique faces of the surface profile. The surface profiles described represent configurations of a surface profile which are cost-effective and easy to manufacture. No complicated secondary or additional treatment of, for example, simple injection-moulded parts, is necessary. It is also conceivable for a reset switch to use mechanical scanning in order to reduce the power consumption of the injection apparatus. As compared to a non-contact variant of the reset switch, in which the status of the apparatus is measured approximately every 1 to two milliseconds, the power consumption can be significantly reduced using a mechanical switch.
Embodiments of the present invention, including preferred embodiments, have been presented for the purpose of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms and steps disclosed. Obvious modifications or variations are possible in light of the teachings herein. The embodiments were chosen and described to provide the best illustration of the principals of the invention and its practical application, and to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth they are fairly, legally, and equitably entitled.
| Number | Date | Country | Kind |
|---|---|---|---|
| 103 30 985.3 | Jul 2003 | DE | national |
This application is a continuation of International Patent Application No. PCT/CH2004/000397, filed on Jun. 25, 2004, which claims priority to German Application No. DE 103 30 985.3, filed on Jul. 9, 2003, and the entire content of both applications is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CH04/00397 | Jun 2004 | US |
| Child | 11327843 | Jan 2006 | US |
