Patent Description:
Diabetes is a group of diseases characterized by high levels of blood glucose resulting from the inability of diabetic patients to maintain proper levels of insulin production when required. Diabetes can be dangerous to the affected patient if it is not treated, and it can lead to serious health complications and premature death. However, such complications can be minimized by utilizing one or more treatment options to help control the diabetes and reduce the risk of complications.

The treatment options for diabetic patients include specialized diets, oral medications and/or insulin therapy. The main goal of diabetes treatment is to control the diabetic patient's blood glucose or sugar level. However, maintaining proper diabetes management may be complicated because it has to be balanced with the activities of the diabetic patient. Type <NUM> diabetes (T1D) patients are required to take insulin (e.g., via injections or infusion) to move glucose from the bloodstream because their bodies generally cannot produce insulin. Type <NUM> diabetes (T2D) patients generally can produce insulin but their bodies cannot use the insulin properly in order to maintain blood glucose levels within medically acceptable ranges. In contrast to people with T1D, the majority of those with T2D usually do not require daily doses of insulin to survive. Many people are able to manage their condition through a healthy diet and increased physical activity or oral medication. However, if they are unable to regulate their blood glucose levels, they will be prescribed insulin. For example, there are an estimated <NUM> million Type <NUM> diabetes patients (e.g., in the United States, Western Europe and Canada) taking multiple-daily-injections (MDI) which consist of a <NUM>-hour basal insulin and a short acting rapid insulin that is taken at mealtimes for glycemic management control.

For the treatment of Type <NUM> diabetes (T1D) and sometimes Type <NUM> diabetes (T2D), there are two principal methods of daily insulin therapy. In the first method, diabetic patients use syringes or insulin pens to self-inject insulin when needed. This method requires a needle stick for each injection, and the diabetic patient may require three to four injections daily. The syringes and insulin pens that are used to inject insulin are relatively simple to use and cost effective.

Another effective method for insulin therapy and managing diabetes is infusion therapy or infusion pump therapy in which an insulin pump is used. The insulin pump can provide continuous infusion of insulin to a diabetic patient at varying rates in order to more closely match the functions and behavior of a properly operating pancreas of a non-diabetic person that produces the required insulin, and the insulin pump can help the diabetic patient maintain his/her blood glucose level within target ranges based on the diabetic patient's individual needs. Infusion pump therapy requires an infusion cannula, typically in the form of an infusion needle or a flexible catheter, that pierces the diabetic patient's skin and through which infusion of insulin takes place. Infusion pump therapy offers the advantages of continuous infusion of insulin, precision dosing, and programmable delivery schedules.

In infusion therapy, insulin doses are typically administered at a basal rate and in a bolus dose. When insulin is administered at a basal rate, insulin is delivered continuously over <NUM> hours in order to maintain the diabetic patient's blood glucose levels in a consistent range between meals and rest, typically at nighttime. Insulin pumps may also be capable of programming the basal rate of insulin to vary according to the different times of the day and night. In contrast, a bolus dose is typically administered when a diabetic patient consumes a meal, and generally provides a single additional insulin injection to balance the consumed carbohydrates. Insulin pumps may be configured to enable the diabetic patient to program the volume of the bolus dose in accordance with the size or type of the meal that is consumed by the diabetic patient. In addition, insulin pumps may also be configured to enable the diabetic patient to infuse a correctional or supplemental bolus dose of insulin to compensate for a low blood glucose level at the time when the diabetic patient is calculating the bolus dose for a particular meal that is to be consumed.

Insulin pumps advantageously deliver insulin over time rather than in single injections, typically resulting in less variation within the blood glucose range that is recommended. In addition, insulin pumps may reduce the number of needle sticks which the diabetic patient must endure, and improve diabetes management to enhance the diabetic patient's quality of life. For example, many of the T2D patients who are prescribed insulin therapy can be expected to convert from injections to infusion therapy due to an unmet clinical need for improved control. That is, a significant number of the T2D patients who take multiple-daily-injections (MDI) are not achieving target glucose control or not adhering sufficiently to their prescribed insulin therapy.

Typically, regardless of whether a diabetic patient uses multiple direct injections (MDIs) or a pump, the diabetic patient takes fasting blood glucose medication (FBGM) upon awakening from sleep, and also tests for glucose in the blood during or after each meal to determine whether a correction dose is required. In addition, the diabetic patient may test for glucose in the blood prior to sleeping to determine whether a correction dose is required, for instance, after eating a snack before sleeping.

To facilitate infusion therapy, there are generally two types of insulin pumps, namely, conventional pumps and patch pumps. Conventional pumps require the use of a disposable component, typically referred to as an infusion set, tubing set or pump set, which conveys the insulin from a reservoir within the pump into the skin of the user. The infusion set consists of a pump connector, a length of tubing, and a hub or base from which a cannula, in the form of a hollow metal infusion needle or flexible plastic catheter, extends. The base typically has an adhesive that retains the base on the skin surface during use. The cannula can be inserted into the skin manually or with the aid of a manual or automatic insertion device. The insertion device may be a separate unit required by the user.

Another type of insulin pump is a patch pump. Unlike a conventional infusion pump and infusion set combination, a patch pump is an integrated device that combines most or all of the fluidic components, including the fluid reservoir, pumping mechanism and mechanism for automatically inserting the cannula, in a single housing which is adhesively attached to an infusion site on the patient's skin, and does not require the use of a separate infusion or tubing set. A patch pump containing insulin adheres to the skin and delivers the insulin over a period of time via an integrated subcutaneous cannula. Some patch pumps may wirelessly communicate with a separate controller device (as in one device sold by Insulet Corporation under the brand name OmniPod®), while others are completely self-contained. Such devices are replaced on a frequent basis, such as every three days, when the insulin reservoir is exhausted or complications may otherwise occur, such as restriction in the cannula or the infusion site.

Medical devices, such as patch pumps, which can be activated by a user to infuse potentially harmful substances, need to have a means to distinguish between valid or intentional user activation of controls and inadvertent activation of controls. Conventional devices provide several means of preventing inadvertent activation, ranging from electrically interlinked buttons to physical structures which prevent the accidental activation of controls.

However, conventional controls rely on complicated mechanical structure for activation buttons or switches to prevent accidental activation. Other conventional controls rely on, for example a two-button activation where the two buttons or switches are electrically interlinked and require precise manipulation to achieve activation.

Accordingly, there is a need for a user-activated fluid delivery system that provides protection from inadvertent activation by the user, while avoiding complicated mechanical structures for activation buttons and/or electrical interconnection of activation buttons or switches requiring precisely ordered or simultaneous activation.

<CIT> discloses a portable medical device being operated in an active mode in which the device receives a user input and an input interlace and provides the received user input to a processor of the device. An infusion system disclosed therein comprises a user interface showing one or more buttons whose simultaneous activation within a time window allows the user to activate the device for operation.

<CIT> discloses a portable therapeutic fluid delivery device for delivering a therapeutic fluid into a body of a patient.

<CIT> discloses a switch operated therapeutic agent delivery device including a switch that can be operated by a user.

<CIT> discloses a method to ensure a safe start, without compromising the safety function, by preventing the mechanical start by the logical product of the signal from timers arranged on respective push-button switch.

An object of the present invention is to substantially address the above and other concerns, and provide a medical device for infusing medical substances which distinguishes between intentional and inadvertent activation of controls by employing a microprocessor to analyze the timing of activation signals from user controls.

Another object of the present invention is to provide a computer implemented signal processing algorithm to facilitate analysis of signals received from multiple activation switches associated with a medical device to prevent inadvertent activation of the medical device.

Another object of the present invention is to provide a medical device for infusing medical substances with easily accessible activation controls, such as activation buttons, that can be conveniently manipulated by a user without causing inadvertent infusion of a medical substance.

Another object of the present invention is to provide activation controls, such as activation buttons for a medical device for infusing medical substances, having a discernable tactile feel to a user, while ensuring that unintentional manipulation of such controls does not cause inadvertent infusion of a medical substance.

In accordance with an aspect of illustrative embodiments of the present invention, a medical device for infusing medical substances comprises an interface for initiating at least two independent time traces based on user input; and a controller evaluating said time traces to command infusing of medical substance based on a conditional relationship between said time traces.

In accordance with an aspect of illustrative embodiments of the present invention, the user input can comprise a first user input and a second user input, and the at least two independent time traces comprise a first time trace and a second time trace. The user interface comprises a first user accessible activation control receiving the first user input and a second user accessible activation control receiving the second user input. The interface selectively initiates the first time trace based on the first activation control receiving the first user input, and selectively initiates the second time trace based on the second activation control receiving the second user input.

In accordance with an aspect of illustrative embodiments of the present invention, the conditional relationship depends on at least one the first start time, the first stop time, a first duration, the second start time, the second stop time, and a second duration.

In accordance with an aspect of illustrative embodiments of the present invention, the device can employs overlap of respective time traces initiated by activation of the activation buttons to determine whether activation is intended and valid. These time traces do not have to be initiated simultaneously or in any particular sequence.

In accordance with an aspect of illustrative embodiments of the present invention, the activation buttons can be elastomeric overmolded buttons set within cutouts in the housing, and, when depressed, make physical contact with respective switches.

The present invention may comprise a method or apparatus for operating a device with activation button(s) having one or more of the above aspects, and/or one or more of the features and combinations thereof.

The above and/or other aspects and advantages of embodiments of the invention will be more readily appreciated from the following detailed description, taken in conjunction with the accompanying drawings, in which:.

Throughout the drawing figures, like reference numbers will be understood to refer to like elements, features and structures.

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

It will be understood by one skilled in the art that this disclosure 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. The embodiments herein are capable of other embodiments, and capable of being practiced or carried out in various ways. Also, it will be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 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 up, down, bottom, and top are relative, and are employed to aid illustration, but are not limiting.

Likewise, it will be understood by one skilled in the art that, unless otherwise explicitly stated in the detailed description that follows, relative and/or specific dimensions of various parts and components shown in the drawing figures are non-limiting examples provided to facilitate understanding of various illustrative implementations of the embodiments of the present invention.

While the illustrative embodiments are described with reference to diabetes management using insulin therapy, it is to be understood that these illustrative embodiments can be used with different drug therapies and regimens to treat other physiological conditions than diabetes using different medicaments than insulin.

<FIG> is a perspective view of an illustrative embodiment of a medicine delivery device comprising a patch pump <NUM> according to an illustrative embodiment of the invention. The patch pump <NUM> is illustrated with a see-through cover for clarity and illustrates various components that are assembled to form the patch pump <NUM>. <FIG> is an exploded view of the various components of the patch pump of <FIG>, illustrated with a solid cover <NUM>. The various components of the patch pump <NUM> may include: a reservoir <NUM> for storing insulin; a pump <NUM> for pumping insulin out of the reservoir <NUM>; a power source <NUM> in the form of one or more batteries; an insertion mechanism <NUM> for inserting an inserter needle with a catheter into a user's skin; control electronics <NUM> in the form of a circuit board with optional communications capabilities to outside devices such as a remote controller and computer, including a smart phone; a pair of dose buttons <NUM> on the cover <NUM> (e.g., one button per side) for actuating an insulin dose, including a bolus dose; and a base <NUM> to which various components above may be attached via fasteners <NUM>. The patch pump <NUM> also includes various fluid connector lines that transfer insulin pumped out of the reservoir <NUM> to the infusion site.

<FIG> is a perspective view of an alternative design for a patch pump 1A having a flexible reservoir 4A, and illustrated without a cover. The aspect of a flexible reservoir 4A is not according to the invention and is present for illustration purposes only. Such arrangement may further reduce the external dimensions of the patch pump 1A, with the flexible reservoir 4A filling voids within the patch pump 1A. The patch pump 1A is illustrated with a conventional cannula insertion device 7A that inserts the cannula, typically at an acute angle, less than <NUM> degrees, at the surface of a user's skin. The patch pump 1A further comprises: a power source 5A in the form of batteries; a metering sub-system <NUM> that monitors the volume of insulin and includes a low volume detecting ability; control electronics 8A for controlling the components of the device; and a reservoir fill port <NUM> for receiving a refill syringe (e.g., syringe <NUM> in <FIG>) to fill the reservoir 4A.

<FIG> is an example patch pump fluidic architecture and metering sub-system diagram of the patch pump 1A of <FIG>. The power storage sub-system for the patch pump 1A includes batteries 5A. The control electronics 8A of the patch pump 1A may include a microcontroller <NUM>, sensing electronics <NUM>, pump and valve controller <NUM>, sensing electronics <NUM>, and deployment electronics <NUM>, that control the actuation of the patch pump 1A. The patch pump 1A includes a fluidics sub-system that may include a reservoir 4A, volume sensor <NUM> for the reservoir 4A, a reservoir fill port <NUM> for receiving a refill syringe <NUM> to refill the reservoir 4A. The fluidics sub-system may include a metering system <NUM> comprising a pump and valve actuator <NUM> and an integrated pump and valve mechanism <NUM>. The fluidics sub-system may further include an occlusion sensor <NUM>, a deploy actuator <NUM>, as well as the cannula <NUM> for insertion into an infusion site on the user's skin. The architecture for the patch pumps of <FIG> and <FIG> can be the same or similar to that which is illustrated in <FIG>.

<FIG> illustrates a wearable medical delivery device (e.g., insulin delivery device (IDD) such as patch pump <NUM>) operable in conjunction with a remote wireless controller (WC) <NUM> that communicates with the pump <NUM>. The aspect of a WC is not according to the invention and is present for illustration purposes only. The WC can comprise a graphical user interface (GUI) display <NUM> for providing a user visual information about the operation of the patch pump <NUM> such as, for example, configuration settings, an indication when a wireless connection to the patch pump is successful, and an indication when a dose is being delivered, among other display operations. In an illustrative implementation, the GUI display <NUM> can include a touchscreen display functionality programmed to allow a user to provide touch inputs such as a swipe to unlock, swipe to confirm a request to deliver a bolus, and selection of confirmation or settings buttons, among other user interface operations.

The WC can communicate with the delivery device (e.g., patch pump <NUM>) using any one or more of a number of communication interfaces <NUM>. For example, a near field radiation interface can be provided to synchronize the timing of the WC and patch pump <NUM> and otherwise facilitate pairing upon start up. Another interface can be provided for wireless communication between the WC and the patch pump <NUM> that employs a standard BlueTooth Low Energy (BLE) layer, as well as Transport and Application layers. Non-limiting examples of Application layer commands include priming, delivering basal dose, delivering bolus dose, cancelling insulin delivery, checking patch pump <NUM> status, deactivating the patch pump <NUM>, and patch pump <NUM> status or information reply.

<FIG> is a top view of an outer housing <NUM> of a medicine delivery device comprising a patch pump <NUM> according to an illustrative embodiment of the invention, including two push buttons <NUM>, <NUM> accessible to a user for initiating delivery of medicine contained in the device. In an illustrative implementation where the WC is employed, certain predetermined manipulation of buttons <NUM>, <NUM> can be used to synchronize communication and facilitate pairing between medicine delivery device and the WC.

As further illustrated in <FIG>, in an illustrative implementation of medicine delivery device comprising a patch pump <NUM>, initiation of medicine delivery (e.g., "bolus") can be performed by operation of buttons <NUM>, <NUM> (for example, a user depressing one or both buttons) to cause respective (e.g., electrical) switches <NUM>, <NUM> to output respective activation signals to a controller <NUM> (e.g., signal processing as illustrated in <FIG>) which can be disposed within the housing <NUM>. In order to distinguish between valid or user intended activation and inadvertent activation of switches <NUM>, <NUM>, the controller processes the activation signals (for example, utilizing a microprocessor such as microcontroller <NUM> in <FIG> and internal or external non-transient computer readable medium) and controls delivery of medicine based on results of the processing as described in more detail with reference to <FIG> and <FIG>.

Referring to diagrams of <FIG>, according to illustrative embodiments of the present invention, timing of the activation signals can be used to verify whether a user intended to initiate delivery of medicine when causing the activation signals. In an illustrative implementation of the present invention for an infusion device with two buttons, such as devices whose features are illustrated in <FIG>, as each button <NUM> and button <NUM> (such as button <NUM> and button <NUM>) is pushed, a respective timer <NUM> and <NUM> can be activated by activation signals from respective switches SW1 and SW2 (such as switches <NUM> and <NUM>) for a respective set amount of time (for example, th1 and th2, where th1 may or may not be equal to th2).

If the time-trace of each timer overlaps with one another, as illustrated in <FIG>, a valid activation is registered. If one timer expires before the other is activated, as illustrated in the example of <FIG>, an invalid activation is registered. Similarly, a time activation of only one timer (for example, as a result of pushing only a respective one of the two buttons <NUM>, <NUM>) is registered as an invalid activation.

As will be appreciated by one skilled in the art, a timer can be implemented in hardware, for example as a timing circuit using discrete electrical components, or in software, for example as a counter using computer executable instructions. The usage of timers as a way to classify button pushes as valid or invalid could potentially mean fewer parts than a physical interlocking type of design, which would translate to lowered cost and assembly time.

Referring to <FIG>, according to an illustrative embodiment of the present invention, a controller <NUM>, such as a programmable microprocessor, monitors outputs of switches SW1 and SW2, such as electrical switches <NUM> and <NUM>, in order to control dispensing of medicine based on valid activation of buttons <NUM> and <NUM> as follows.

When a user operates ("push <NUM>") button <NUM>, switch (SW1) <NUM> outputs an activation signal (sig1) <NUM>, and when a user operates ("push <NUM>") button <NUM>, switch (SW2) <NUM> outputs an activation signal (sig2) <NUM>. Controller <NUM> performs computer executable instructions including:.

Notably, the two signals <NUM> and <NUM> (e.g., sig1 and sig2) can be processed independently and/or in parallel with each other.

According to illustrative embodiments of the present invention as illustrated in the non-limiting examples of <FIG> and <FIG>, the determination whether an activation to dispense medicine is valid (e.g., intended by the device user) does not require buttons <NUM> and <NUM> to be pushed in a certain sequence or simultaneously. Instead, the determination whether an activation to dispense medicine is valid is based on an overlap of respective time traces initiated by respective activation signals caused by pushing respective buttons <NUM> and <NUM>. These time traces do not have to be initiated simultaneously, or in any particular sequence, because the overlap is simply based on the two time traces being present together for a certain time period, i.e., the overlap, as illustrated in <FIG>. For example, <FIG> shows button <NUM> pushed before button <NUM>; however, the same valid activation can be achieved by pushing button <NUM> before button <NUM>, as shown in <FIG>.

The duration of the overlap constituting a valid activation can be preset, or for example, programmed in a non-transient computer readable memory internal or external to controller <NUM>. Likewise, the duration of activation signals, th1 and th2 can be preset, or for example, programmed in a non-transient computer readable memory internal or external to controller <NUM>, and can be independently set to different or same durations with respect to one another. Thus, according to an illustrative implementation of the present invention, the determination whether an activation to dispense medicine is valid can be based on the setting for the overlap, th1 and th2, which can be independently preset, programmed, or adjusted, for example in a non-transient computer readable memory internal or external to controller <NUM>. Programming of the button activation parameters such as the duration of the overlap, th1 and th2 can depend on any of a number of factors such as, for example, locations of the buttons on the device, user ergonomics and/or habits, and structural requirements of the medical delivery device. For example, the button activation parameters can depend on any one or more of: bounce associated with the contacts of the switches, human factor considerations (e.g., timing associated with typical user manipulation of the device), tactile feedback qualities of a particular mechanical button implementation, among other factors.

<FIG> illustrate illustrative implementations of various housing and push button ("bolus button") structures for medicine delivery devices or infusion devices. These structures are not according to the invention and are present for illustration purposes only. They can be utilized independently of, or in conjunction with, the controller <NUM> and the timing analysis according to illustrative embodiments of the present invention.

Illustrative implementations of the present inventions may address several functional requirements for a bolus button on an infusion device such as, for example, a button design which reliably registers valid pushes while minimizing inadvertent pushes, while also sealing against ingress to the interior of the infusion device.

<FIG> illustrate a top and side view of a housing of a medicine delivery device <NUM> including a rigid shell <NUM> and push buttons <NUM> and <NUM> with an overmolded elastomer to provide a seal and improved user grip. The aspect of an overmolded elastomer is not according to the invention and is present for illustration purposes only. In this illustrative implementation, in order to activate electrical switches, which can be mounted on a printed circuit board <NUM>, as illustrated in <FIG>, the user needs to push the buttons <NUM>, <NUM> on the outer housing with a force of sufficient magnitude and travel to be applied to these switches for activation.

In an illustrative implementation a rigid flex arm can be provided under the overmolded button <NUM>, <NUM> to enlarge the area which a user can push on the button and still create a sufficient activation force on the electrical switch. <FIG> illustrate a side view of a housing <NUM> without the overmold to show examples of a flex arm for illustration purposes. In particular, <FIG> illustrates an example of a flex arm <NUM> with a smaller cutout <NUM> which would produce a stiffer flex arm <NUM>. On the other hand, <FIG> illustrates an example of a more flexible flex arm <NUM> due to a larger cut out <NUM>. The overall shape of the cutout <NUM> or <NUM> and the total cutout area can vary depending on the materials (e.g., material type, thickness, flexibility) used for the housing cover or shell <NUM> and overmolded elastomer, and the desired flexibility or stiffness or travel distance needed to activate the switch <NUM>, <NUM> corresponding to the button <NUM>, <NUM>.

<FIG> illustrate side and cross section (along respective lines A-A, B-B, C-C, D-D) views of an elastomeric overmold. In illustrative implementations, such overmold is intended to provide a seal against foreign substances from entering the interior of the housing of a medicine delivery device. It is also an interface for the user to interact with the device (for example to activate switches <NUM>, <NUM> as described above with reference to <FIG>). The illustrative implementations of an elastomeric overmold shown in <FIG> can emphasize or deemphasize certain characteristics of this interface.

Illustrative implementations of an elastomeric overmold as illustrated in <FIG> provide designs <NUM> and <NUM>, respectively, which have features <NUM> and <NUM>, respectively, that would not protrude from, or be flush with, the outer body, which provides a lesser chance of inadvertent activation.

Illustrative implementations of an elastomeric overmold as illustrated in <FIG> provide designs <NUM> and <NUM>, respectively, which have features <NUM> and <NUM>, respectively, that would protrude from the main surface of the housing. Such an illustrative implementation may provide a positional tactile cue for the user, which may be particularly useful if the user does not have a line of sight to the device (e.g., the user is wearing the patch pump <NUM> adhered to the skin of the abdomen and under clothing).

An additional feature of illustrative implementations of an elastomeric overmold as illustrated in <FIG>, <FIG> is a groove <NUM>, <NUM> and <NUM>, respectively, around a portion of the button which reduces the cross section of the elastomer, which would in turn lower the force needed to flex the button.

According to embodiments that are shown for illustration purposes, an elastomeric overmold design, as illustrated in <FIG> has an advantage of being a system of designs tunable for the desired forces and feel. For example, a lower force combination would be the large cutout flex arm, as illustrated in <FIG> coupled with the indented rectangle of <FIG>.

The housing cover or shell <NUM> or button <NUM>, <NUM> can have an interior (i.e., relative to the contents of the housing <NUM>) surface area or interior attribute (e.g., ridge or rib such as rib <NUM> in <FIG>) that is disposed directly opposite and apart from the corresponding switch <NUM>, <NUM> when the button <NUM>, <NUM> is not depressed, and that comes into contact (e.g., physical contact) with the switch <NUM>, <NUM> when the button <NUM>, <NUM> is depressed. The buttons <NUM>, <NUM> can be mounted on or formed with the housing <NUM> in such a manner that depression of a button <NUM> or <NUM> causes the corresponding interior surface area or attribute to translate, move or otherwise extend toward the corresponding switch <NUM>, <NUM>.

For example, with reference to <FIG>, an outer housing of a device <NUM> (e.g., a medicine delivery device such as a patch pump) is provided with elastomer activation buttons <NUM>, <NUM>. The design of the outer housing is not according to the invention and is present for illustration purposes only. For example, the outer housing can be formed from a rigid material indicated at <NUM> such as plastic with holes or cutouts indicated at <NUM> configured such that the elastomer activation buttons <NUM>, <NUM> are two shot molded into the space defined by the holes or cutouts <NUM>. The housing <NUM>, switches <NUM>, <NUM>, and elastomer activation buttons <NUM>, <NUM> are disposed such that, when a user pushes on, depresses or otherwise activates the activation buttons <NUM>, <NUM>, the inner surface of each elastomer activation button <NUM>, <NUM> pushes the corresponding switch <NUM>, <NUM> (e.g., a tactile switch or other type of switch <NUM>, <NUM> mounted on or adjacent to the printed circuit board <NUM>). When depressed, the elastomer activation buttons <NUM>, <NUM> can push the corresponding switches <NUM>, <NUM> directly, or indirectly (e.g., via an intervening member not shown), to activate the switch. For example, activation of the switch <NUM>, <NUM> can be the result of a first part of the switch coming into electrical contact with an electrode or other part of the switch or printed circuit board on or near which the switch is mounted within the device to generate a signal output (e.g., indicating button activation and processed by the controller <NUM>), thereby changing the switch <NUM>, <NUM> from an inactive state to an active state). The interior surface of each elastomer activation button <NUM>, <NUM> can be provided with a rib <NUM> or other physical attribute as illustrated in <FIG>, <FIG> and <FIG>; however, a rib <NUM> may not be required depending on the materials used for the buttons <NUM>, <NUM>, the type of switch <NUM>, <NUM>, the arrangement of the housing <NUM>, switch <NUM> or <NUM> and button <NUM> or <NUM>, respectively, relative to each other, and the desired human number factors such as the desired amount of pressure required by the user to activate the switch without false activation and the desired tactile feedback.

Claim 1:
A medical device for infusing medical substances comprising:
an interface for starting at least two independent timers based on user input;
wherein said timers are configured in that a respective time-out can be assigned to each of them; and
a controller (<NUM>) evaluating traces of said timers to command infusing of medical substance based on a conditional relationship between the traces of said timers; and
a housing (<NUM>) configured to accommodate said controller (<NUM>), a first user accessible button (<NUM>, <NUM>) and a second user accessible button (<NUM>, <NUM>);
wherein said user input comprises a first user input and a second user input;
said at least two independent timers comprise a first timer and a second timer,
wherein said first timer having a respective first time-out and said second timer having a respective second time-out;
said interface comprises a first user accessible activation control receiving said first user input and a second user accessible activation control receiving said second user input;
said interface selectively starting said first timer based on said first activation control receiving said first user input;
said interface selectively starting said second timer based on said second activation control receiving said second user input;
wherein said first user accessible activation control comprises said first user accessible button, and
said second user accessible activation control comprises said second user accessible button;
said first user input and said second user input processed independently and in parallel with each other;
wherein the device is configured to
check whether the first timer has timed out;
check whether the second timer has timed out; and
if the first timer and the second timer have not timed out, validate an activation for dispensing medicine.