The present invention relates to a device for delivering medication to a patient.
Various infusion systems exist that utilize devices for delivering liquid medication or other therapeutic fluid to patients subcutaneously. For patients with diabetes mellitus, for example, conventional infusion systems incorporate various pumps that are used to deliver insulin to a patient. These pumps have the capability of delivering assorted fluid delivery profiles which include specified basal rates and bolus requirements. For example, these pumps include a reservoir to contain the liquid medication along with electromechanical pumping technology to deliver the liquid medication via tubing to a needle that is inserted subcutaneously into the patient.
Although such conventional pumps/infusion systems are adequate for their intended purpose, such pumps have difficult controlling drug delivery precisely thereby causing harm to the patient. That is, these pumps have large stroke volumes resulting in inaccurate basal rate infusion and incorrect insulin dosing. Further, with these infusion systems, diabetes patients must install and carry at least two bulky and obtrusive devices on their bodies. This causes significant inconvenience for the patient during his/her daily activities.
Therefore, it would be advantageous to provide an improved infusion system over these conventional infusion systems.
A device is disclosed for delivering medication to a patient.
In accordance with an embodiment of the present disclosure, a device is disclosed for delivering a medication to a patient in a drug infusion system. The device is configured as a fully autonomous and integrated wearable apparatus for managing the medication delivery. The device comprises a reservoir for storing the medication to be delivered to the patient; a continuous glucose monitoring device for monitoring glucose levels in the patient to set flow rates for medication delivery; a needle for delivering the medication from reservoir into the patient; and a pumping unit including one or more MEMS devices configured to function as (a) a pump for pumping the medication from the reservoir through a flow path for medication to the needle at set flow rates and/or (b) a valve for regulating flow of the medication in the flow path from the reservoir through the needle.
In accordance with another embodiment of the disclosure, a device is disclosed for delivering a medication to a patient in a drug infusion system. The device is configured as a fully autonomous and integrated wearable apparatus for managing the medication delivery. The device comprises a continuous glucose monitoring device for monitoring glucose levels in the patient to set flow rates for medication delivery to the patient; a reservoir for storing the medication to be delivered to the patient; a needle for delivering the medication from reservoir into the patient; and first and second MEMS devices in communication with the reservoir, continuous glucose monitoring device and needle, each MEMS device configured to function as a pump for pumping the medication along a flow path of medication from the reservoir to the needle at the set flow rates, wherein the first and second MEMS devices comprise first and second pumping sections, respectively, including first and second pumping chambers.
In accordance with another embodiment of the disclosure, a device configured as a fully autonomous and integrated wearable apparatus for managing insulin delivery is disclosed. The device comprises a continuous glucose monitoring device for monitoring glucose levels in the patient to set flow rates for medication delivery to the patient; a reservoir for storing the medication to be delivered to the patient; a needle for delivering the medication from reservoir into the patient; and a plurality of MEMS devices in communication with the reservoir, continuous glucose monitoring device and needle, each MEMS device of the plurality of MEMS devices configured to function as a pump for pumping the medication along a flow path from the reservoir to the needle at the set flow rates and wherein each of the plurality of MEMS devices each includes a pumping section comprising a pumping chamber, an actuator and a membrane between the actuator and pumping chamber, whereby the actuator causes membrane to move and drive insulin from or into the pumping chamber.
Infusion system 100 includes device 102 (or pod) for delivering insulin to a diabetes of other fluid medication to a patient. In this configuration, device 102 incorporates one or more micro-electro-mechanical systems (MEMS) devices into its architecture for motive force and sensing functionality (as described in more detail below). Among other benefits, the MEMS technology (layers) in device 102 architecture enables direct connection between fluid path components for infusion without any tubing, connectors and/or separate mechanical valves. As a result, device 102 not only produces greater precision in pumping volume, it requires less power for operation, has better reliability, and less drug waste held up in fluid pathways (smaller dead volume). (In addition, MEMS manufacturing results in a very accurate device dimension with low tolerance (e.g, 1 um)). Consequently, device 12 may be fabricated to a significantly smaller scale. In short, by incorporating MEMS technology, device 102 is configured as a fully autonomous and integrated wearable unit or apparatus for diabetes management in which continuous glucose monitoring (CGM), insulin delivery and closed loop control are provided together to ensure insulin is delivered at very precise rates. Device 102 details appear below. (Note that MEMS devices are also known as microsystem technology and micromachined devices).
Device 102 includes reservoir 104, pumping unit or element 106 (also may be referred to as a micropump), microcontroller unit (MCU) 108, insulin delivery needle 110, glucose monitoring components 112 including the CGM (device), a sensor and needle (percutaneously inserted in the patient), and battery and power controller 114. CGM, as known to those skilled in the art, tracks patient glucose levels and permits those levels to be used in algorithms that control flow rate. MCU 108 controls the operation of pumping unit 106 as described below.
Reservoir 104 is configured to receive and store insulin for its delivery over a course of about three days, or as needed. However, reservoir size may be configured for storing any quantity of fluid as required.
Pumping unit 106 fluidly communicates with reservoir 104 to enable infusion as needed. In one example configuration, pumping unit 106 may connect directly to reservoir 104 by bonding and/or adhesive with corresponding holes in alignment. In another example configuration, a short interposer may be used as a connector. In practice, the interposer functions as a funnel. The interposer consists of two plates of glass and/or silicon bonded together to form a plurality of holes and channels which may be employed to transition one size opening to another between pumping unit 106 to reservoir 104. These are examples. Those skilled in the art know that other connector options may be used to achieve desired results. Pumping unit 106 also fluidly communicates with insulin needle 110 for insulin delivery. Insulin needle 110 and/or a cannula itself surrounding needle 110 may be inserted directly into pumping unit 106. Alternatively, a similar interposer may also be used to connect needle 110 or cannula to pumping unit 106. In this configuration, a plate covering the larger end of the interposer includes several holes to ensure proper fluid transfer in any orientation. Examples of these connections are shown and described below with respect to
Pumping unit 106 incorporates MEMS devices that function as a pump for pumping fluid such as insulin, valves for regulating flow, actuators for moving or controlling the pump and valves, and sensors for sensing pressure, insulin flow, presence of air in the fluid path and across the channels in the MEMS devices. In one example configuration, the MEMS devices are each a piezoelectric transducer (or other MEMS devices including capacitive transducers or piezoresistive transducers) that acts as the active element for pumping fluid, but other MEMS structures or technology may be used to achieve desired results as known to those skilled in the art. Operation and functional details of the MEMS devices (e.g., piezoelectric transducer) appear in more detail below.
MCU 108 electronically communicates with the actuator and sensors in pumping unit 106 as well as the CGM sensor, as the monitoring components 112 in
Battery and power controller 114 controls the power to MCU 108 and pumping unit 106 to enable those components to function properly as known to those skilled in the art. The CGM is powered by battery and power controller 114 through MCU 108.
Infusion system 100 further includes mobile device 116 that wirelessly communicates with the communications circuitry on an ASICs chip along with MCU 108. Communication circuitry communicates with the MCU 108 as known to those skilled in the art. Communication may be achieved using Bluetooth, WIFI, NFC or other means of communication known to those skilled in the art. The application on mobile device 116 wirelessly communicates with one or more medical professionals via cloud 118 (via cellular, WIFI or other) as known to those skilled in the art. An application on mobile device 118 functions to receive, analyze and visualize data generated by device 102. The application will upload any configurations, settings and firmware updates when paired with device 102 upon startup. The application on mobile device 116 will also send data to cloud 118.
In
In the first instance, the insulin dosing control loop automatically monitors and determines (i.e., sets) a proper flow rate for the patient. Specifically, CGM (monitoring components 112) tracks (measures) patient glucose levels which are converted to instructions for flow rate by control algorithms as known to those skilled in the art. The control algorithms residing on MCU 108 controls and commands the pumping unit 106 (MEMS devices as valves and pumping elements as described below) to deliver insulin through insulin needle 110 from reservoir 104 at that flow rate, based on the CGM converted data. This represents the first control loop which utilizes MCU 108, CGM and pumping unit 106.
In the second instance, the control loop actively and automatically monitors the actual flow rate to ensure that the set flow rate is delivered precisely as originally commanded, i.e., to ensure that the actual flow rate monitored is the same as the flow rate commanded. As the first step, MCU 108 will set an initial flow rate as determined above, i.e., a voltage and frequency, as well as a driving waveform, for a patient and the pumping unit 104 will pump at that flow rate. Next, a flow sensor measures the actual flow rate (Q) off pumping unit 106 (MEMS device as described herein). At the same time, CGM (monitoring component 112) measures the glucose level in the patient and converts that glucose level to a flow rate (S). Then, MCU 108 will then compare the flow rate (S) with the actual flow rate (Q) sensed. That is, MCU 108 will measure (calculate) the difference ((S−Q)) (also known as an error signal) and command pumping unit 106 to adjust the initial flow rate by changing the voltage and/or frequency of pumping unit 106. This operation will automatically continue, in a looping fashion, until the error signal is reduced to zero. Once at zero, pumping unit 106 will continue pumping at the same flow rate until alternate rate instructions come from the control algorithms residing on the MCU. In short, pumping unit 106 will increase or decrease voltage and/or frequency to adjust flow rate from pumping unit 106 (MEMS device) in accordance with the error signal generated. This represents the second control loop which utilizes MCU 108, CGM, pumping unit 106 (and flow sensor as part of pumping unit 106).
Insulin is initially stored in reservoir 200-9 and delivered through inlet valve 200-2, pump 200-3 (pumping chamber), outlet valve 200-4, pressure sensors 200-5 with at least one hydraulic resistor and infusion set 200-6. The valves may be active valves controlled by MCU 200-7 (or ASIC), or the valves may be passive valves such as check valves without a driver known to those skilled in the art. Pump 200-3 is driven by electronics to withdraw insulin from reservoir 200-9 through inlet valve 200-2, and to pump insulin out of the pump 200-3 to infusion set 200-6 through outlet valve 200-4. The delivery flow rate is captured by pressure sensors 200-5, as well as the occlusion detection is sensed by at least one pressure sensor. This is similarly described above with respect to an embodiment above.
Also similar to the embodiment in
Inlet valve 300, pumping section 302 and outlet valve 304 function together to withdraw insulin (or other fluid) from reservoir 104 and drive the insulin at selected rates to the patient dictated by the CGM. Operation is described as follows. As shown in
Next, inlet valve 300 is closed by the inlet valve actuator 302-1, by changing the position of the inlet valve membrane onto an opposing surface or edge. Then, pumping membrane 302-2 is moved back into pumping chamber 302-2 by pumping actuator 302-1 driven in that direction, thereby increasing pressure in pumping chamber 302-3. With pumping membrane 302-2 sweeping the volume of pumping chamber 302-3, thereby increasing pressure therein, outlet valve 304 is opened with outlet valve actuator 302-1. This is shown in
At the exit region of the MEMS devices, pressure sensor and flow sensor sense pressure and flow as identified in
In addition to pressure and flow sensing, air bubble sensing is performed in the flow path to determine if bubbles are present in the fluid path. In an example configuration, the air sensor uses an ultrasonic device to measure time-of-flight for sound waves changing velocity of transmission between air and insulin (fluid) solution. That is, once air volume is determined, it is subtracted from the volume of insulin dosage to alert and/or adjust for lack of dosing.
These sensors will transmit information to MCU 108 and processed via software to provide real-time adjustments to fluid flow and pressure as needed per patient as well as alert/alarm signals for conditions present. The adjustments in flow rate may be accomplished in two ways. First, flow rate may be adjusted by increasing pulse frequency of the actuators in the inlet, pumping and outlet chambers. Second, flow rate may be adjusted by increasing the voltage of each pulse to the pumping actuator. This increase in voltage ultimately causes an increase in amplitude of deflection of the pumping membrane. These real-time adjustments in flow will yield significantly improved flow precision, pulsatility and accuracy. However, there are other ways to adjust flow and/or pressure. Examples of this appear in
As for alerts and alarms, MCU 108 may also provide signals for alarm/alert conditions such as low flow and excess pressure (both indicating occlusion for example) causing a potential under-dosing of the patient. In addition, the alarm/alert will alert of conditions such as presence of air indicating absence of drug dosing or possibly an empty reservoir/end of dose, as well as conditions of flow in excess of that set by the insulin dosing control algorithm.
As described above, inlet and outlet valve actuators 300, 304 are shown and described as an active design in which the inlet and outlet valve actuators are configured with moving parts, i.e., a piezoelectric transducer actuator retracts a membrane to enable fluid flow. In the passive design, the inlet valve actuator and outlet valve actuator function passively. That is, the inlet valve actuator and outlet valve actuator are configured without moving parts such as in a diffuser valve. In essence, the inlet and outlet valve actuators are considered not be present. Passive valves are described below in more detail.
Also note, that inlet valve 300 and outlet valve 304 are MEMS devices shown are sized and configured (i.e., fabricated) similarly. MEMS device 302, as the pumping section, is configured with a larger chamber than the chambers of the inlet and outlet valves. This is one example configuration for these MEMS devices. However, MEMS devices 300, 302, 304 may be configured and fabricated to various sizes and/or constructions to achieve desired pressure and flow rate as known to those skilled in the art.
In
In
In
In
In brief, during suction operation, pumping section 396 is driven to enable higher chamber volume which creates a negative pressure in the chamber to open the inlet flap valve 392-1. During the pumping operation, pumping section 396 is driven to have a smaller chamber volume which creates a positive pressure in the chamber to open outlet flap valve 394. Fluid will flow through inlet valve 392 and out outlet valve 394 (by way of flaps 392-1 and 394-1) as shown by the arrows.
In
The expandable element and dual flaps of these valves 392, 394 are secured to wall of the pumping unit 390 as an integral piece or as a bonded or attached piece as known to those skilled in the art. The expandable element and flaps will bend or bow off of an opening to enable liquid (fluid) medication to move into and out of chamber 396-3 (through channels as shown by arrows) of pump 396 as shown.
In
As noted above, devices (102, 600, 700) are described for delivering insulin to a diabetes patient. However, these devices may be used to deliver other medications such as small molecule pharmaceutical solutions, large molecule or protein drug solutions, saline solutions, blood or other fluids known to those skilled in the art.
It is to be understood that the disclosure teaches examples of the illustrative embodiments and that many variations of the invention can easily be devised by those skilled in the art after reading this disclosure and that the scope of the present invention is to be determined by the claims below.
This application claims priority to U.S. provisional application No. 62/923,099, filed on Oct. 18, 2019 entitled “Device For Delivering Medication To a Patient,” which is incorporated by reference herein.
Filing Document | Filing Date | Country | Kind |
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PCT/US2020/055845 | 10/15/2020 | WO |
Number | Date | Country | |
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62923099 | Oct 2019 | US |