METHOD FOR CONTROLLING ELECTROCHEMICAL PUMP AND ELECTROCHEMICAL PUMP IMPLEMENTING THE SAME

Disclosed is a method for controlling an electrochemical pump, comprising: providing an electrochemical pump, and causing a control circuit of the electrochemical pump to generate a pulse signal to enable an electrochemical reaction on electrodes of the electrochemical pump, wherein the pulse signal has alternating on-periods and off-periods where the pulse signal is off, and wherein each on-period has a plurality of on-times where the pulse signal is on and a plurality of off-times where the pulse signal is off, the on- and off-times being alternatingly arranged.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for controlling an electrochemical pump.

2. Description of the Prior Art

Injection, such as hypodermic injection or intravenous injection, is a common-seen method to deliver medicine into bodies. At present, pen-type injectors and electronically controlled injectors, such as patch-type injectors, wearable injectors and implanted injectors, have been developed to enable users to inject medicine into their own bodies by themselves. The conventional pen-type injectors utilize springs to generate driving force to deliver medicine which may cause sharp pain during injection, therefore, the pen-type injector can only inject small amount of medicine due to the pain, and cannot be used for injection of a large amount of medicament.

One electronically controlled injector delivers medicine via the driving force provided by a motor. The injection time and injection dosage can be controlled via controlling motor rotation. However, the electronically controlled injector with the motor is difficult to be miniaturized and is inconvenient for the patient for long-term carrying/wearing. Another conventional electronically controlled injector is only suitable to deliver insulin. For other macromolecular drugs (or biologics), such as monoclonal antibody, hormone, growth factor, and etc., the existing electronically controlled injectors are challenging of providing sufficient driving forces, especially in the case of delivering drugs in pre-filled containers (e.g., pre-filled syringe or pre-filled cartridge) due to the airtight seal between the rubber plunger and the glass of these containers. Further, to extend the lifetime of the electronically controlled injector devices, power administration is also critical and requires cutting-edge solutions.

Accordingly, it is highly desirable to provide a new pump technology capable of overcoming the abovementioned problems.

SUMMARY OF THE INVENTION

The present invention provides a method for controlling an electrochemical pump. The method comprises the following steps: (i) providing an electrochemical pump comprising a substrate having an electrode region, a plurality of electrodes disposed in the electrode region, a dam enclosing the electrode region to define an accommodating space, an electrochemical liquid disposed in the accommodating space, and a control circuit electrically connected with the electrodes; and (ii) causing the control circuit to generate a pulse signal to enable an electrochemical reaction on surfaces of the electrodes. The pulse signal has alternating on-periods and off-periods where the pulse signal is off. In addition, each on-period has or is composed of a plurality of on-times where the pulse signal is on, and a plurality of off-times where the pulse signal is off, wherein the on- and off-times are alternatingly arranged.

Also provided is an electrochemical pump comprising: a substrate having an electrode region; a plurality of electrodes disposed in the electrode region; a dam enclosing the electrode region to define an accommodating space, the accommodating space storing an electrochemical liquid; a control circuit electrically connected to the electrodes; and a non-transitory machine-readable storage medium connected to the control circuit, including instructions that, when executed by the control circuit, causes the control circuit to: generate a pulse signal to enable an electrochemical reaction on surfaces of the electrodes, wherein the pulse signal has alternating on-periods and off-periods where the pulse signal is off, and wherein each on-period has a plurality of on-times where the pulse signal is on and a plurality of off-times where the pulse signal is off, the on- and off-times being alternatingly arranged.

Preferably, the pulse signal in each on-periods has a same amplitude, a same frequency, and a same duty cycle.

The on-times may have a frequency ranging from about 1 Hz to about 1 GHz.

According to certain embodiments of the present invention, the on-times have a frequency ranging from about 1 Hz to about 1 kHz. In such embodiments, the on- and off-times may be configured to have a duty cycle of about 50%, 55%, 60%, 65%, 70%, 75%, or more.

According to certain embodiments of the present invention, the on-times have a frequency ranging from about 1 kHz to about 1 MHz. In such embodiments, the on- and off-times may be configured to have a duty cycle of about 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or more.

According to certain embodiments of the present invention, the on-times have a frequency ranging from about 1 MHz to about 1 GHz. In such embodiments, the on- and off-times may be configured to have a duty cycle of about 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or 75%.

It was unexpectedly found in the present invention that a pulse signal of the present invention can achieve a delivery efficiency for an electrochemical pump similar to that resulted from a conventional pulse signal which is all “on” during its on-periods. As such, a method for controlling an electrochemical pump of the present invention has an advantage of power-saving.

The present invention also provides an electrochemical pump and a delivery device thereof, wherein a hybrid pulse is used to control the electrochemical reaction, whereby power is effectively saved and the lifetime of the electrochemical pump is significantly prolonged.

The present invention provides another electrochemical pump and a delivery device thereof, wherein edges of electrodes are covered with an insulating layer to protect the bonding between the electrodes and a substrate to allow high-power electrochemical reaction for high flow rate and/or large driving force.

In one embodiment, the electrochemical pump of the present invention comprises a substrate, a plurality of electrodes, a dam, and a control circuit. The substrate has an electrode region. The electrodes are disposed in the electrode region. The dam encircles the electrode region and defines an accommodating space. The accommodating space stores an electrochemical liquid. The control circuit is electrically connected with the electrodes and uses a pulse signal to selectively activate an electrochemical reaction on surfaces of the electrodes, wherein an enabling pulse of the pulse signal includes a plurality of sub-enabling pulses.

In one embodiment, the delivery device of the present invention comprises an electrochemical pump, a container, and a delivery connector. The electrochemical pump comprises a substrate, a plurality of electrodes, a dam, and a control circuit. The substrate has an electrode region. The electrodes are disposed in the electrode region. The dam encircles the electrode region and defines an accommodating space. The accommodating space stores an electrochemical liquid. The control circuit is electrically connected with the electrodes and uses a pulse signal to selectively activate an electrochemical reaction on surfaces of the electrodes, wherein an enabling pulse of the pulse signal includes a plurality of sub-enabling pulses. The container includes a sealing element and a piston. A liquid, which is to be delivered, is stored between the sealing element and the piston. The container is connected with the electrochemical pump, whereby an airtight room is defined between the piston and the accommodating space of the electrochemical pump. The delivery connector includes a tube, a puncture element and a delivery element. The puncture element is connected with one end of the tube and used to puncture the sealing element of the container, whereby the container is interconnected with exterior through puncture element. The delivery element is connected with another end of the tube and disposed on an object. The delivered liquid is pushed by the piston to arrive the object through the puncture element, the tube and the delivery element.

In another embodiment, the electrochemical pump of the present invention comprises a substrate, a plurality of electrodes, an insulating layer, a dam, and a control circuit. The substrate has an electrode region. The electrodes are disposed in the electrode region. The insulating layer covers edges of the electrodes and a portion of the electrodes is exposed. The dam encircles the electrode region and defines an accommodating space. The accommodating space stores an electrochemical liquid. The control circuit is electrically connected with the electrodes, selectively activating an electrochemical reaction on surfaces of the electrodes.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description is merely intended to illustrate various embodiments of the invention. As such, specific embodiments or modifications discussed herein are not to be construed as limitations to the scope of the invention. It will be apparent to one skilled in the art that various changes or equivalents may be made without departing from the scope of the invention.

In order to provide a clear and ready understanding of the present invention, certain terms are first defined. Additional definitions are set forth throughout the detailed description. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as is commonly understood by one of skill in the art to which this invention belongs.

As used herein, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component” includes a plurality of such components and equivalents thereof known to those skilled in the art.

As used herein, the term “comprise” or “comprising” is generally used in the sense of include/including which means permitting the presence of one or more features, ingredients or components. The term “comprise” or “comprising” encompasses the term “consists” or “consisting of.”

In one aspect, the present invention provides a method for controlling an electrochemical pump. The method comprises providing an electrochemical pump and causing a control circuit of the electrochemical pump to generate a pulse signal to enable an electrochemical reaction. The electrochemical pump comprises a substrate having an electrode region, a plurality of electrodes disposed in the electrode region, a dam enclosing the electrode region to define an accommodating space, an electrochemical liquid disposed in the accommodating space, and a control circuit electrically connected with the electrodes.

In another aspect, the present invention provides an electrochemical pump comprising:a substrate having an electrode region;a plurality of electrodes disposed in the electrode region;a dam enclosing the electrode region to define an accommodating space, the accommodating space storing an electrochemical liquid;a control circuit electrically connected to the electrodes; and a non-transitory machine-readable storage medium connected to the control circuit, including instructions that, when executed by the control circuit, causes the control circuit to:generate a pulse signal to enable an electrochemical reaction on surfaces of the electrodes,wherein the pulse signal has alternating on-periods and off-periods where the pulse signal is off, andwherein each on-period has a plurality of on-times where the pulse signal is on and a plurality of off-times where the pulse signal is off, the on- and off-times being alternatingly arranged.

The pulse signal applied to the electrodes by the control circuit has alternating on-periods and off-periods where the pulse signal is off. In addition, each on-period has or is composed of a plurality of on-times where the pulse signal is on, and a plurality of off-times where the pulse signal is off, wherein the on- and off-times are alternatingly arranged.

According to the present invention, the on-times may have a frequency ranging from about 1 Hz to about 1 GHz.

In some embodiments, the on-times have a frequency ranging from about 1 Hz to about 1 kHz. In such embodiments, the on- and off-times may be configured to have a duty cycle of about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or more, and up to about 99.99%.

In some other embodiments, the on-times have a frequency ranging from about 1 kHz to about 1 MHz. In such embodiments, the on- and off-times may be configured to have a duty cycle of about 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90%.

In some embodiments, the on-times have a frequency ranging from about 1 MHz to about 1 GHz. In such embodiments, the on- and off-times may be configured to have a duty cycle of about 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or 75%.

Conventionally, a pulse signal for enabling an electrochemical pump may have a typical frequency of about 0.00167 Hz (1/10/60 Hz) and a typical duty cycle of about 50% (e.g., PWM1inFIG.7A). By contrast, a waveform of a pulse signal of the present invention may be obtained by adding a plurality of periodical off-times in each on-periods of a conventional pulse signal to result in clusters of pulses (periodically generated “sub-pulse signals”) having a frequency within each on-periods much higher than that of the conventional pulse signal (e.g., 5 Hz for PWM2inFIG.7A).

According to certain preferred embodiments of the present invention, the pulse signal in each on-periods has a same amplitude, a same frequency, and a same duty cycle (more specifically, each sub-pulse signals may have a same duration of on-times and a same duration of off-times. In other words, the pulse signal in each on-periods may have a substantially same waveform.

As shown inFIGS.7A and7B, a pulse signal of the present invention PWM2demonstrates a delivery efficiency for an electrochemical pump (volume of delivered liquid) similar to that of a conventional pulse signal PWM1. However, PWM2uses substantially less power than PWM1(about 50% less power, in view that the duty cycle for PWM2during an on-period is about 50%). In addition, for pulses in an on-period set at a higher frequency, a duty cycle of less than 50% (e.g., about 45%, 40%, 35%, 30%, or as low as about 25%) may be used, while maintaining a delivery efficiency similar to that of a conventional counterpart.

Please refer toFIG.1. In one embodiment, the delivery device of the present invention comprises an electrochemical pump10, a container20and a delivery connector30. The container20includes a sealing element21and a piston22. A storage space23is formed between the sealing element21and the piston22for storing a liquid, which is to be delivered. For example, the liquid to be delivered may be a drug or biologics such as monoclonal antibody. However, the liquid is not limited to be water-based fluid. The liquid may be a solvent-based fluid (such as DMSO) or an oil-based fluid (such as corn oil). In one embodiment, the container20may be a pre-filled container (prefilled syringe or prefilled cartridge).

The delivery connector30includes a tube31, a puncture element32and a delivery element33. The puncture element32is connected to one end of the tube31and used to puncture the sealing element21of the container20, whereby the storage space23of the container20is interconnected with the exterior of the container20through puncture element32. The delivery element33is connected to another end of the tube31and is to be disposed on an object. For example, the delivery element33may be inserted or implanted hypodermically, subcutaneously, intramuscularly, intravenously, or intraperitoneally. However, the delivery element33is not limited to be disposed in the abovementioned regions but may also be disposed on another appropriate region. The delivery element33shown inFIG.1is a needle-like structure. However, the delivery element33is not limited to be a needle-like structure but may be a connector, which is to be connected with another syringe or delivery instrument. Thereby, the delivery device of the present invention may be remote from the position where the drug is to be delivered. For example, the delivery device may be worn on the arm, abdomen, thigh or hips of a patient, and the needle is inserted into the adjacent area of the aforementioned position of the patient.

According to the abovementioned structure, after the puncture element32of the delivery connector30punctures the sealing element21of the container20, the liquid (such as a drug), which is stored inside the storage space23for delivery, may be delivered through the puncture element32, the tube31and the delivery element33to the object via pushing the piston22.

The structure of the electrochemical pump10will be described in detail below. The electrochemical pump10of the present invention comprises a substrate11, a plurality of electrodes12aand12b, a dam13, and a control circuit15. The substrate11has an electrode region111, and the electrodes12aand12bis disposed in the electrode region111of the substrate11. In one embodiment, the substrate11is made of glass, quartz, ceramic, semiconductor material or plastic. For example, the ceramic may be aluminum oxide or titanium oxide etc.; the semiconductor material may be silicon. The dam13encircles the electrode region111of the substrate11and defines an accommodating space for storing an electrochemical liquid14. The control circuit15is electrically connected with the electrodes12aand12b. For example, the substrate11includes a plurality of electric-conduction contacts12c, and the control circuit15includes electric-conduction contacts151. Via leads or another appropriate means (such as connector or pogo pin), the electric-conduction contacts151of the control circuit15are electrically connected with the plurality of electric-conduction contacts12c. Thereby, the control circuit15is electrically connected with the electrodes12aand12b. The control circuit15includes necessary electronic elements152(such as a microcontroller and passive elements) and electric-conduction contacts153for electric conduction with a power supply16(such as a battery). Neither the detailed structure of the control circuit15nor the connection means of the power supply16is the primary technical characteristic of the present invention. Therefore, they will not repeat herein.

The container20is connected with the electrochemical pump10, and an airtight room24is defined between the piston22of the container20and the accommodating space formed by the dam13. For example, an engagement structure corresponding to the container20is formed in the dam13; while the container20is disposed into the engagement structure of the dam13, the container20and the dam13define an airtight room24between the piston22and the electrochemical liquid14. The control circuit15selectively supplies power to the electrodes12aand12bto selectively enable an electrochemical reaction on the surfaces of the electrodes12aand12band generate gas. This additional gas increases the pressure inside the airtight room24and thus pushes the piston22to move.

In the embodiment shown inFIG.1, the dam13contacts the outer wall of the container20to form the airtight room24. However, the present invention is not limited by this embodiment. Please refer toFIG.2. In one embodiment, the dam13contacts the inner wall of the container20to form the airtight room24. In the embodiment shown inFIG.2, the airtight room24interconnects with the accommodating space formed by the dam13through a passage131. Thereby, the gas generated by the electrochemical reaction enters the airtight room24through the passage131to increase the pressure inside the airtight room24.

It would be appreciated that the design that the passage131is used to interconnect the airtight room24and the accommodating space formed by the dam13facilitates different designs of the relative position of the container20and the substrate11. In the embodiments shown inFIG.1andFIG.2, the container20is vertical to the substrate11. However, the present invention is not limited to these embodiments. Please refer toFIG.3. In one embodiment, the container20is parallel to the substrate11. It should be noted: the present invention is not limited by the embodiments that the container20and the electrochemical pump10are directly connected to each other. In other embodiments, appropriate adapters may be used to connect the container20and the dam13, whereby different containers or layouts may be used.

Please refer toFIG.4. In one embodiment, the electrochemical pump10comprises an insulating layer121, which covers the edges of the electrodes12aand12band reveals a portion of the electrodes12aand12b, whereby to prevent from delamination of the electrodes. According to the abovementioned structure, the insulating layer121may increase the bonding strength between the substrate11and the electrodes12aand12b, decrease the chance that gas enters the interfaces between the substrate11and the electrodes12aand12b, and thus prevent from electrode delamination in a high-power electrochemical reaction. In one embodiment, the insulating layer121is made of epoxy (such as solder mask, SU-8), photo patternable polymer, photo patternable silicone, glass, ceramic, or plastic. For example, the photo patternable polymer includes photo resist, photo patternable polyimide, and photo patternable adhesives. In one embodiment, the insulating layer121can be formed by screen printing, semiconductor manufacturing, or sintering.

As mentioned above, the control circuit15selectively supplies power to enable an electrochemical reaction and generate gas on the surfaces of the electrodes12aand12b. Please refer toFIG.5. In one embodiment, the control circuit15uses the pulse signal shown inFIG.5to selectively enable an electrochemical reaction on the surfaces of the electrodes12aand12b. The pulse signal shown inFIG.5includes two enabling pulses P1. It would be appreciated that the width W1of the enabling pulse P1may be modified according to a target delivery output of the electrochemical pump10. For example, while the width W1of the enabling pulse P1is larger, the triggered electrochemical reaction is longer, and more gas is generated. Contrarily, while the width W1of the enabling pulse P1is smaller, the triggered electrochemical reaction is shorter, and less gas is generated. It would be appreciated that because the response of the electrochemical reaction is slower in comparison with the change of electric signal, gas is still generated between two enabling pulses P1. Therefore, appropriately adjusting the width W1of the enabling pulse P1may generate a required amount of gas and save energy. In one embodiment, the pulse signal according to the present invention can be realized by pulse width modulation (PWM) technology. It would be appreciated that setting the widths W1of the enabling pulses P1to be the same can also generate a predetermined amount of gas.

Particularly, in one embodiment, the enabling pulse P1includes a plurality of sub-enabling pulses P2. The enabling pulse P1is primary pulse width modulation and the sub-enabling pulse P2is for a secondary pulse width modulation. Preferably, a width of the enabling pulse is 1/600 Hz, and a duty cycle of the enabling pulse is 50%, and a width of the sub-enabling pulse is 5 Hz, and a duty cycle of the sub-enabling pulse is 50%. In other words, while the enabling pulse P1enables the electrochemical reaction, it does not activate the electrochemical reaction continuously but triggers the electrochemical reaction intermittently. Similar to that mentioned above, gas is still generated between two sub-enabling pulses P2. Therefore, the enabling pulse P1formed by a plurality of sub-enabling pulses P2may save energy furthermore. In one embodiment, the width W2of the sub-enabling pulses P2may be the same. It would be appreciated that the width W2of the sub-enabling pulses P2may be modified to adjust the target output of the electrochemical pump10.

As mentioned above, one of the applications of the delivery device of the present invention is to deliver medicine to an object. Therefore, how to guarantee sterilization of the delivery path between the container20and the object is an important subject. Please refer toFIG.6for the solution of the abovementioned problem. In one embodiment, the delivery connector30further comprises a casing34, and the tube31, the puncture element32and the delivery element33are arranged in the interior of the casing34. The casing34includes a first opening341and a second opening342, wherein the puncture element32is corresponding to the first opening341and the delivery element33is corresponding to the second opening342. The first opening341and the second opening342are respectively sealed by sealing membranes343. Then, the delivery connector30having the abovementioned structure is sterilized. Thus, the interior of the casing34is maintained in a sterilized state. In other words, the tube31, the puncture element32and the delivery element33are all in a sterilized state. In this embodiment, the electrochemical pump10and the container20are disposed inside a housing17. While the present invention is to be used, the delivery connector30and a housing17are correspondingly assembled together. Thus, the puncture element32punctures the sealing membrane343on the first opening341and the sealing element21of the container20. Similarly, the delivery element33punctures the sealing membrane on the second opening342and then is implanted into an appropriate position of the object. Thereby, the drug delivery path between the container20and the object is maintained in a sterilized state. In one embodiment, the sealing membrane on the first opening341and on the second opening342can be removed before the puncture element32is to puncture the sealing element21and the delivery element33is implanted into the object.

According to the abovementioned structure, it should be noted that the delivery connector30, the container20and the electrochemical pump10may be fabricated by different manufacturers respectively and then assembled together to form a complete product. Thus, the high temperature used to sterilize the delivery connector30would not affect the stability of the drug in the container20. Further, the demand to the cleanness of the environment where the parts are assembled together is lowered.

It would be appreciated that the outer surface of the sealing membrane343will be polluted after sterilization because it may contact the external environment. Therefore, a sterilizing process, such as swabbing the outer surface of the sealing membrane343, may be used to decrease the risk of the pollution of the drug delivery path. Refer toFIG.6for an embodiment that can simplify the sterilization operation. InFIG.6, the delivery connector30further comprises a protection layer344, which is disposed on the outer surface of the sealing membrane343. According to the abovementioned structure, while the present invention is to be used, only removing the protection layer344is sufficient to guarantee the sterilized state of the sealing membrane343. Therefore, the protection layer344can secure the sterilization of the sealing membrane343and simplify the operation process of using the present invention.

In conclusion, the electrochemical pump and the delivery device of the present invention use hybrid pulses to control an electrochemical reaction, whereby electric energy is effectively saved and the usage time of the electrochemical pump is significantly prolonged. Further, an electrochemical pump and a delivery device of the present invention includes an insulating layer covering the edges of the electrodes to enhance the bonding strength between the electrodes and the substrate and decrease the chance that gas enters the interfaces between the electrodes and the substrate, whereby to prevent from electrode delamination.