Portable infusion pump and portable infusion system

Abstract

The invention provides a portable infusion pump and a portable infusion system. The portable infusion pump comprises a driving device, a pushing piece, a non-contact type asymptotic switch and a control module. The driving device is used for driving the pushing piece to move towards the far-end direction or the near-end direction along an axis under the control of the control module; when the pushing piece moves towards the far end, the pushing piece is used for pushing a piston rod of the liquid storage device. The control module is configured to control the driving device to drive the pushing piece to move towards the near end when receiving a replacement installation signal, and control the driving device to stop driving the pushing piece and update the initial position information of the pushing piece based on the corresponding relation between the current position of the pushing piece and the trigger position of the non-contact asymptotic switch; the control module is further configured to control the driving device to drive the pushing piece to move according to the driving amount corresponding to the injection signal on the basis of the current initial position information when the injection signal is received.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a portable infusion pump and a portable infusion system. BACKGROUND

[0002] At present, the main strategy for the treatment of diabetes is insulin injection, which can be achieved by wearing a portable infusion pump or manual injection. Due to the cumbersome management of manual injection and the demand for privacy of personal health status, the research and development of portable infusion pumps are more meaningful for improving the quality of life of such patients.

[0003] In the existing portable infusion pump, the running position of the piston is calculated by converting the running angle or stroke of the motor rotating structure, so as to calculate the injection amount. The piston rod of the driving device is reused for a long time, which will accumulate position errors and reduce the injection accuracy. SUMMARY

[0004] The present application aims to provide a portable infusion pump and a portable infusion system to solve the problem of long-term precision reduction of the existing portable infusion pump.

[0005] To solve the above technical problems, the present application provides a portable infusion pump, which comprises a driving device, a pushing member, a non-contact progressive switch and a control module. The driving device is used to drive the pushing member to move along an axis in a distal direction or a proximal direction under the control of the control module; when the pushing member moves in the distal direction, it is used to push the piston rod of the liquid reservoir. The control module is configured to, when receiving a replacement installation signal, control the driving device to drive the pushing member to move in the proximal direction, and based on the corresponding relationship between the current position of the pushing member and the trigger position of the non-contact progressive switch, control the driving device to stop driving the pushing member and update the starting position information of the pushing member. The control module is further configured to, when receiving an injection signal, control the driving device to drive the pushing member to move according to the driving amount corresponding to the injection signal based on the current starting position information.

[0006] Optionally, the step of controlling the driving device to drive the pushing member to move according to the driving amount corresponding to the injection signal based on the current starting position information comprises: The control module calculates the remaining liquid amount of the liquid reservoir according to the starting position information and the sum of the driving amounts recorded in all injection processes before the current injection process. If the remaining liquid volume is not less than a target injection volume corresponding to the current injection signal, a target driving volume of the driving device is calculated according to the target injection volume, the driving device is controlled to drive the pushing member to move in the distal direction according to the target driving volume, and a driving volume of the current injection process is recorded.

[0007] Optionally, if the remaining liquid volume is less than the target injection volume corresponding to the current injection signal, the control module controls the driving device to stop driving the pushing member to move, and sends a replacement prompt signal.

[0008] Optionally, the driving device comprises a motor, and the control module is further configured to collect a current of the motor. The control module is further configured to control the motor to stop operating and send an alarm signal when the current is not less than a preset threshold.

[0009] Optionally, the preset threshold is obtained according to a relationship between a current required to consume a friction force of a piston of the liquid reservoir and a pressure, and a relationship between a current required to consume a friction torque of a transmission component of the driving device and a pressure.

[0010] Optionally, the driving device comprises a driving motor, a lead screw, a reduction gear set and a planetary reducer; the driving motor drives the lead screw to rotate around the axis in sequence through the planetary reducer and the reduction gear set; the pushing member is threadedly connected with the lead screw in a matching manner, and the pushing member is limited to rotate around the circumference of the lead screw.

[0011] Optionally, the driving device comprises a base body, the reduction gear set comprises a driven gear and two bearings, the two bearings are arranged on both sides of the driven gear along the axis, and the driven gear is rotatably accommodated in the base body through the two bearings; one end of the lead screw is a free end, and the other end is coaxially connected with the driven gear.

[0012] Optionally, the portable infusion pump comprises a housing; the driving device comprises a base body, the base body and the housing jointly enclose a liquid reservoir cavity, the liquid reservoir cavity is used for replaceably accommodating the liquid reservoir therein; the pushing member and the lead screw are accommodated in the liquid reservoir cavity; The base body has a through hole opened along the axis, the reduction gear set has a connecting shaft, the connecting shaft passes through the through hole and is connected with the lead screw; the connecting shaft and the through hole form a dynamic seal.

[0013] Optionally, the corresponding relationship comprises a positional relationship between the pushing member and the non-contact progressive switch when the pushing member moves in the proximal direction to a trigger position corresponding to the non-contact progressive switch.

[0014] To address the aforementioned technical problems, this application also provides a portable infusion system, which includes the portable infusion pump described above, and a reservoir; the reservoir includes a piston rod for connecting to the pusher.

[0015] Optionally, the piston rod has an inner cavity opened along the axis, the inner cavity being for the lead screw of the drive device to enter, so that when the piston rod is connected to the pusher, it avoids the lead screw.

[0016] In summary, in the portable infusion pump and portable infusion system provided in this application, the portable infusion pump includes a driving device, a pusher, a non-contact progressive switch, and a control module. The driving device is used to drive the pusher to move along an axis in a distal or proximal direction under the control of the control module. When the pusher moves in the distal direction, it pushes the piston rod of the reservoir. The control module is configured to, upon receiving a replacement installation signal, control the driving device to drive the pusher to move in the proximal direction, and based on the correspondence between the current position of the pusher and the trigger position of the non-contact progressive switch, control the driving device to stop driving the pusher and update the starting position information of the pusher. The control module is also configured to, upon receiving an injection signal, based on the current starting position information, control the driving device to drive the pusher to move by a driving amount corresponding to the injection signal.

[0017] With this configuration, the position of the pusher can be determined without contact using a non-contact progressive switch. Each time the reservoir is replaced, the starting position information of the pusher is updated, effectively recalibrating the pusher's starting position every time the reservoir is replaced. This prevents the drive unit from accumulating positional errors during long-term reuse. Attached Figure Description

[0018] Those skilled in the art will understand that the accompanying drawings are provided to better understand this application and do not constitute any limitation on the scope of this application. Wherein: Figure 1 This is a schematic diagram of the main body of the portable infusion system according to an embodiment of this application.

[0019] Figure 2 This is an exploded view of a portable infusion system according to an embodiment of this application.

[0020] Figure 3 yes Figure 1 The figure shown is a perspective view of the main body of the portable infusion system according to an embodiment of this application.

[0021] Figure 4This is a schematic diagram of the functional modules of a portable infusion pump according to an embodiment of this application.

[0022] Figure 5 This is a flowchart illustrating the control logic of a portable infusion pump according to an embodiment of this application.

[0023] Figure 6 This is a schematic diagram of a driving device according to an embodiment of this application.

[0024] Figure 7 This is an exploded view of the driving device according to an embodiment of this application.

[0025] Figure 8a This is a schematic diagram illustrating the relationship between current and pressure required for interference items in this application embodiment. Figure 1 .

[0026] Figure 8b This is a schematic diagram illustrating the relationship between current and pressure required for interference items in this application embodiment. Figure 2 .

[0027] In the attached diagram: 1-Portable infusion pump; 10-Housing; 100-Reservoir chamber; 11-Drive unit; 110-Base; 1101-Through hole; 111-Motor; 112-Lead screw; 113-Reduction gear set; 1131-Driven gear; 1132-Bearing; 1133-Interval wheel; 1134-Connecting shaft; 1135-Drive gear; 114-Planetary reducer; 1141-Constraint bearing; 115 - Mounting slot; 116 - Sealing part; 12 - Pushing part; 121 - Rotation limiting protrusion; 13 - Non-contact progressive switch; 14 - Control module; 141 - Encoder; 15 - Reservoir cover; 151 - First external thread; 152 - First internal thread; 16 - Interaction device; 2 - Reservoir; 20 - Cylinder; 21 - Piston rod; 210 - Inner cavity; 22 - Piston; 23 - Outlet; 3 - Infusion set; 4 - Battery. Detailed Implementation

[0028] To make the objectives, advantages, and features of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, used only to facilitate and clarify the illustration of the embodiments of this application. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and sometimes use different scales.

[0029] As used in this application, the singular forms “a,” “an,” “one,” and “the” include plural objects; the term “or” is generally used to mean “and / or”; the term “a number” is generally used to mean “at least one”; and the term “at least two” is generally used to mean “two or more”. Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as “first,” “second,” or “third” may explicitly or implicitly include one or at least two of that feature; “one end” and “the other end,” and “proximal end” and “distal end” generally refer to two corresponding parts, which include not only endpoints. Furthermore, the terms "installed," "connected," and "attached," as used in this application, and the term "set" on one element from another, should be interpreted broadly. They generally only indicate a connection, coupling, cooperation, or transmission relationship between the two elements, which can be direct or indirect through intermediate elements. They should not be construed as indicating or implying a spatial relationship between the two elements, meaning one element can be located inside, outside, above, below, or to one side of another element, unless otherwise explicitly stated. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances. Additionally, directional terms such as above, below, up, down, upward, downward, left, and right are used relative to exemplary embodiments as shown in the figures, with upward or upper directions pointing towards the top of the corresponding figure, and downward or lower directions pointing towards the bottom of the corresponding figure.

[0030] The purpose of this application is to provide a portable infusion pump and a portable infusion system to solve the problem of long-term decreased accuracy of existing portable infusion pumps. The following description refers to the accompanying drawings.

[0031] Please refer to Figures 1 to 7 This application provides a portable infusion system, comprising a portable infusion pump 1 and a reservoir 2. The portable infusion pump 1 is a reusable device, and the reservoir 2 is a replaceable consumable. The reservoir 2 contains a drug solution (such as insulin), and the portable infusion pump 1 drives the reservoir 2 to achieve injection. For ease of description, the direction in which the portable infusion pump 1 drives the reservoir 2 to output the drug solution (i.e., the direction in which the piston 22 of the reservoir 2 squeezes the drug solution) is defined as the distal direction. Figure 1 The example shown represents the left-hand direction. The direction opposite to the distal direction is the proximal direction. Figure 1 The example shown is from the right end.

[0032] To address the long-term accuracy degradation issue of existing portable infusion pumps, this application provides a portable infusion pump 1, comprising: a drive unit 11, a pusher 12, a non-contact progressive switch 13, and a control module 14. The drive unit 11, under the control of the control module 14, drives the pusher 12 to move along an axis A in a distal or proximal direction. When the pusher 12 moves in the distal direction, it pushes the piston rod 21 of the reservoir 2. The control module 14 is configured to, upon receiving a replacement / installation signal, control the drive unit 11 to drive the pusher 12 in the proximal direction, and based on the correspondence between the current position of the pusher 12 and the trigger position of the non-contact progressive switch 13, control the drive unit 11 to stop driving the pusher 12 and update the initial position information of the pusher 12. The control module 14 is also configured to, upon receiving an injection signal, based on the current initial position information, control the drive unit 11 to drive the pusher 12 by a driving amount corresponding to the injection signal. In some embodiments, the correspondence between the current position of the pusher 12 and the trigger position of the non-contact progressive switch 13 includes the positional relationship between the pusher 12 and the non-contact progressive switch 13 when the pusher 12 moves towards the proximal end to the trigger position corresponding to the non-contact progressive switch 13. That is, when the pusher 12 moves to the trigger position, the control module 14 is immediately triggered. In other embodiments, the correspondence is not limited to the positional relationship when the pusher 12 moves exactly to the trigger position corresponding to the non-contact progressive switch 13, but may have a certain positional tolerance or time delay, etc. That is, when the pusher 12 moves to the trigger position, the control module 14 may be triggered after a certain time delay, and the control drive device 11 stops driving the pusher 12, and is not limited to a one-to-one correspondence.

[0033] In one example, such as Figures 1 to 3 As shown, the portable infusion pump 1 has a housing 10, and components such as a drive device 11, a pusher 12, a non-contact progressive switch 13, and a control module 14 are all disposed within the housing 10. Adapted to the portable infusion pump 1 provided in this embodiment, this application also provides a reservoir 2, which includes a cylinder 20, a piston rod 21, and a piston 22. The piston 22 is movably and sealed within the cylinder 20 along its axial direction. The piston rod 21 is connected to the piston 22, thereby allowing the piston rod 21 to drive the piston 22 to move. Optionally, in the initial state, the cavity formed by the cylinder 20 and the piston 22 contains a certain amount of medication, with the piston 22 located at the proximal end of its stroke, at which time most of the proximal end of the piston rod 21 extends outside the cylinder 20.

[0034] Furthermore, the drive device 11 includes a base 110, which, together with the housing 10, forms a reservoir cavity 100, which is used to replaceably accommodate the reservoir 2. Figures 1 to 3In the example shown, the housing 10 has a cavity extending along axis A, and the base 110 (referring to the sealing part 116, as described below) is disposed at the proximal end of the cavity along axis A, thus forming a reservoir cavity 100 that is a blind cavity with a distal opening. The reservoir 2 can enter and exit from the distal opening of the reservoir cavity 100 during installation and removal.

[0035] Furthermore, the portable infusion system also includes an infusion set 3, which is detachably connected to the reservoir 2 to deliver medication. In one embodiment, the portable infusion pump 1 further includes a reservoir cap 15 having a first external thread 151 and a first internal thread 152. The infusion set 3 has a second external thread that mates with the first internal thread 152, so that the infusion set 3 can be threadedly connected to the reservoir cap 15. The distal opening of the reservoir cavity 100 has a second internal thread that mates with the first external thread 151, so that the reservoir cap 15 can be threadedly connected to the housing 10. Optionally, the reservoir 2 has an outlet 23 for dispensing medication and for mounting the infusion set 3. Understandably, when the infusion set 3 is installed on the outlet 23 and secured, since the infusion set 3 and the reservoir cap 15 are connected to the housing 10 via two threads, their positions relative to the housing 10 along axis A can be finely adjusted to accommodate the positional error of the pusher 12 each time it moves to the trigger position of the corresponding non-contact progressive switch 13. Even if the position of the pusher 12 along axis A changes to some extent, it can be adapted through the two threads of the infusion set 3 and the reservoir cap 15, ensuring that the position of the reservoir 2 can be reliably locked after the infusion set 3 and the reservoir cap 15 are installed.

[0036] When the reservoir 2 is installed on the portable infusion pump 1, the piston rod 21 and the pusher 12 can be connected by abutting or engaging. Since the reservoir 2 is a replaceable consumable part, the piston rod 21 is not reused, and the piston rod 21 does not need to contact the housing 10 of the portable infusion pump 1. Therefore, the relative position of the pusher 12 and the piston 22 is essentially fixed. Thus, by locating and calculating the accurate position of the pusher 12, the exact position of the piston 22 can be determined, thereby calculating the amount of liquid in the cylinder 20.

[0037] The control module 14 (e.g., a controller, also referred to as a "controller") preferably has a program or control logic that controls the operation of the drive device 11 according to the program or control logic and in combination with acquired parameters (such as trigger signals of the non-contact progressive switch 13, injection signals, and control signals). Optionally, the portable infusion pump 1 also includes a battery 4, which is preferably built into the housing 10, for providing power to components such as the control module 14, the non-contact progressive switch 13, and the drive device 11.

[0038] The non-contact proximity switch 13 (e.g., Hall effect, photoelectric, eddy current, magnetic, or capacitive sensing sensor) is preferably fixedly mounted inside the housing 10 and can be triggered when the pusher 12 approaches a certain position, for example, by sending a trigger signal to the control module 14.

[0039] When the portable infusion pump 1 replaces the reservoir 2 or installs the reservoir 2 for the first time, a replacement / installation signal (one of the aforementioned control signals) can be sent to the control module 14. For example, the portable infusion pump 1 includes an interactive device 16, which includes buttons, a display screen, or a touch screen. The user sends the replacement / installation signal to the control module 14 through the buttons on the interactive device 16. When the control module 14 receives the replacement / installation signal, it controls the drive device 11 to drive the pusher 12 to move towards the proximal end until the pusher 12 moves to the trigger position corresponding to the non-contact progressive switch 13 (e.g., ...). Figure 3 (As shown in the image), the non-contact gradual switch 13 is triggered, sending a trigger signal to the control module 14. Upon receiving the trigger signal, the control module 14 controls the drive device 11 to stop driving the pusher 12 and updates the starting position information of the pusher 12. Then, a new reservoir 2 can be installed, connecting the piston rod 21 of the reservoir 2 to the pusher 12 (as shown in the image). Figure 3 (See the description below for the status shown).

[0040] After receiving an injection signal (which can be input via an interactive device, or issued based on a timer, preset program, or cloud device), the control module 14 executes the injection. The control module 14 controls the drive device 11 to drive the pusher 12 to move in the distal direction, which in turn pushes the piston rod 21 to move in the distal direction to achieve injection.

[0041] The initial position information could be, for example, the coordinates of the pusher 12. After updating the initial position information of the pusher 12, the control module 14 essentially sets the coordinates of the pusher 12 to zero. Subsequent movements of the pusher 12 will then be calculated from the zero point of the current coordinates. Therefore, after replacing the reservoir 2 of the portable infusion pump 1 or after the initial installation of the reservoir 2, the zero point of the pusher 12's position calculation will be reset and updated, ensuring that the drive device 11 will not accumulate position errors during long-term reuse. Furthermore, this process is achieved through a non-contact progressive switch 13, which avoids introducing additional friction or mechanical wear, further improving the reliability of long-term reuse and preventing the introduction of additional interference during pressure monitoring.

[0042] Optionally, based on the current starting position information, the step of controlling the drive device 11 to drive the pusher 12 to move according to the drive amount corresponding to the injection signal includes: the control module 14 calculates the remaining liquid volume of the reservoir 2 according to the starting position information and the sum of the drive amounts recorded in all previous injection processes; if the remaining liquid volume is not less than the target injection amount corresponding to the current injection signal, the target drive amount of the drive device 11 is calculated according to the target injection amount, the drive device 11 is controlled to drive the pusher 12 to move in the distal direction according to the target drive amount, and the drive amount of this injection process is recorded.

[0043] Understandably, when the control module 14 receives the injection signal for the first time after replacing or installing reservoir 2, since there has been no previous injection process, the total driving quantity recorded in the previous injection processes is zero. The remaining liquid volume in reservoir 2 is its nominal capacity. Generally, the nominal capacity of the reservoir 2 after replacement or initial installation is known and is usually much larger than the target injection volume for each injection. At this time, the control module 14 can calculate the target driving quantity of the drive device 11 based on the target injection volume.

[0044] In one embodiment, the drive device 11 includes a motor 111, a lead screw 112, a reduction gear set 113, and a planetary reducer 114. The motor 111 drives the lead screw 112 to rotate about axis A via the planetary reducer 114 and the reduction gear set 113. The pusher 12 is threadedly connected to the lead screw 112 and is restricted to rotate circumferentially around the lead screw 112. In this embodiment, both the pusher 12 and the lead screw 112 are housed in the reservoir cavity 100. In some embodiments, the reservoir cavity 100 and the pusher 12 have matching rotation-limiting protrusions and rotation-limiting grooves arranged in a direction parallel to axis A. In this embodiment, the rotation-limiting protrusion 121 is provided on the pusher 12, and correspondingly, the reservoir cavity 100 is provided with a rotation-limiting groove (not shown) corresponding to the rotation-limiting protrusion 121. The rotation-limiting protrusion 121 can only move in the rotation-limiting groove along the direction of axis A, thereby restricting the rotation of the pusher 12 so that it can only move in the direction of axis A within the reservoir cavity 100. Furthermore, the pusher 12 is preferably in the form of a flat sheet to minimize friction relative to the reservoir cavity 100.

[0045] Taking the drive device 11, which includes a motor 111, a lead screw 112, a reduction gear set 113, and a planetary reducer 114, as an example, the target drive quantity R0 is also characterized as the target drive stroke of the motor 111 (which can be understood as the target number of rotations of the motor 111). Parameters such as the number of rotations or rotation angle of the motor 111 can be obtained by an encoder 141 installed on the motor 111.

[0046] Specifically, let the reduction ratio of planetary reducer 114 be M1, the reduction ratio of reduction gear set 113 be M2, the thread lead of lead screw 112 be L, and the area of ​​piston 22 of reservoir 2 be S. Then, we can know that the total reduction ratio of planetary reducer 114 and reduction gear set 113 is M = M1 * M2, the target injection volume (target injection volume of drug solution) is V0 = R0 / M * L * S, and the target driving amount is R0 = V0 * M / L / S.

[0047] Upon receiving an injection signal, the control module 14 can obtain the target injection volume V0 for that injection process. In one example, if the target injection volume V0 is included in the injection signal, the control module 14 obtains the target injection volume V0 simultaneously with receiving the injection signal. In another example, the control module 14 can also independently obtain the target injection volume V0 upon receiving the injection signal, such as by reading it through a program or preset information; this embodiment is not limited to this.

[0048] After obtaining the target injection volume V0, the target injection volume V0 is compared with the remaining liquid volume Vs in the reservoir 2. If Vs ≥ V0, it indicates that the remaining liquid volume Vs in the reservoir 2 is sufficient to meet the needs of the current injection process. The control module 14 then drives the motor 111 according to the target drive amount R0 calculated based on the target injection volume V0. When the real-time drive amount R of the motor 111 (i.e., real-time stroke, real-time number of rotations) reaches the target drive amount R0, it indicates that the injection of the drug solution with the target injection volume V0 is completed. During the injection process, the control module 14 also records the drive amount R of the motor 111 during this injection process. Optionally, the remaining liquid volume Vs can also be displayed on the display screen of the interactive device 16 to prompt the user.

[0049] Furthermore, during subsequent injection processes, the control module 14 calculates the current position information (i.e., the current coordinates of the pusher 12) of the pusher 12 based on the initial position information and the total driving volume ΣR recorded from several previous injection processes. Based on the current position information of the pusher 12, the current remaining liquid volume Vs of the reservoir 2 can be calculated. When the control module 14 receives an injection signal, it obtains the target injection volume V0 and compares it with the current remaining liquid volume Vs of the reservoir 2. If Vs ≥ V0, injection is performed as described above. Specifically, when Vs = V0, it means the remaining liquid volume is exactly equal to the current target injection volume V0. After the control module 14 controls the drive device 11 to complete the current injection process, the medication in the reservoir 2 is completely injected. Optionally, after the medication in the reservoir 2 is completely injected, the control module 14 can also issue a replacement prompt signal.

[0050] If the remaining liquid volume Vs is less than the target injection volume V0 corresponding to the current injection signal, the control module 14 controls the drive device 11 to stop driving the pusher 12 and issues a replacement prompt signal. When Vs < V0, it indicates that the remaining liquid volume Vs in the reservoir 2 is insufficient for the current injection process. In this case, it is preferable to stop driving the pusher 12 and issue a replacement prompt signal. The replacement prompt signal can be expressed through sound, light, vibration, or screen display, for example. After receiving the replacement prompt signal, the user can replace the reservoir 2.

[0051] In another embodiment, if the remaining liquid volume Vs is less than the target injection volume V0 corresponding to the current injection signal, the control module 14 controls the drive device 11 to drive the pusher 12 to move towards the distal end according to the remaining drive amount corresponding to the remaining liquid volume Vs, records the remaining liquid volume Vs, and issues a prompt signal indicating replacement and the need for supplementary push after the push is completed, such as displaying a yellow warning light or providing a voice prompt to continue injection. After the replacement is completed, the control module 14 receives the replacement completion signal, calculates the difference drive amount based on the difference between the target injection volume V0 and the remaining liquid volume Vs, and then controls the drive device 11 to drive the pusher 12 to move towards the distal end according to the difference drive amount, and records the drive amount of this injection process (i.e., the difference drive amount). After the difference drive amount is completed, the prompt signal changes accordingly, such as a green indicator light or a voice prompt indicating that the injection is complete. This embodiment makes full use of the remaining liquid in the reservoir 2 and reduces liquid waste.

[0052] In some applications, the portable infusion pump 1 requires high injection accuracy, and the injection volume may be small each time. Therefore, the drive unit 11 preferably provides a high reduction ratio, such as 500~800, so that the single-stroke stroke of the motor 111 can meet the injection accuracy requirements. The combined application of the reduction gear set 113 and the planetary reducer 114 can meet the requirement of a high reduction ratio. In one example, the portable infusion pump 1 is used for infusing insulin, with an insulin concentration C = 100 U / mL. The thread lead L of the lead screw 112 is 0.5 mm, and the area S of the piston 22 of the reservoir 2 is 100 mm². 2 With a reduction ratio M=800, when motor 111 runs half a revolution, i.e., 180°, the driving amount R=0.5. Therefore, the injection accuracy X=(S*L*R*C) / M=0.003U. At this point, the control module 14 can meet the single-step accuracy of 0.003U by controlling the stroke resolution of motor 111 to be higher than 180°.

[0053] In some applications, portable infusion systems are configured for intermittent injection. During periods when infusion is not being administered, it is necessary to maintain the established pressure environment within the injection tubing. Therefore, the drive unit 11 preferably also needs to be self-locking to maintain the pressure within the injection tubing. In some embodiments, the lead screw 112 is a trapezoidal lead screw, meaning that the thread between the lead screw 112 and the pusher 12 is a trapezoidal thread. With a suitable thread lead, a certain degree of self-locking effect can be provided. Furthermore, with the planetary reducer 114 and the high reduction ratio of the reduction gear set 113, self-locking can be achieved when the motor 111 stops without relying on an additional brake structure, preventing the pusher 12 from retracting.

[0054] Please refer to Figure 6 and Figure 7 Optionally, the reduction gear set 113 includes a driven gear 1131, two bearings 1132, an intermediate gear 1133, and a driving gear 1135, with the driven gear 1131, intermediate gear 1133, and driving gear 1135 meshing sequentially. In some embodiments, the number of intermediate gears 1133 can be set according to the reduction ratio and the spatial dimensions of the base 110; there can be one, two, or more intermediate gears 1133. The driving gear 1135 is connected to the output shaft of the planetary reducer 114, and the input end of the planetary reducer 114 is connected to the output shaft of the motor 111. Thus, the output shaft of the motor 111 drives the driving gear 1135 through the planetary reducer 114, which in turn drives the driven gear 1131 through the intermediate gear 1133. In some embodiments, the driven gear 1131, intermediate gear 1133, and driving gear 1135 are arranged in a Z-shape to reduce the volume of the reduction gear set 113.

[0055] In one example, the base 110 has a reduction gear receiving cavity, in which the reduction gear set 113 is received. Further, the base 110 includes a sealing portion 116, which together with the housing 10 encloses the reservoir cavity 100 and isolates the reservoir cavity 100 from the reduction gear receiving cavity.

[0056] Since the installation and removal of the reservoir 2 are coaxial with the lead screw 112, the driven gear 1131 and the two bearings 1132 are arranged at one axial end of the lead screw 112, thus avoiding the distal opening of the reservoir cavity 100. However, this arrangement also brings certain problems. Because the distal end of the lead screw 112 is a free end and the proximal end is connected to the driven gear 1131, the lead screw 112 forms a cantilever structure. The cantilever structure of the lead screw 112 is prone to radial wobble at the cantilever end (i.e., the distal end).

[0057] Therefore, in this embodiment, two bearings 1132 are arranged along axis A on both sides of the driven gear 1131, and the driven gear 1131 is rotatably housed in the base 110 via the two bearings 1132; one end of the lead screw 112 is a free end, and the other end is coaxially connected to the driven gear 1131. By arranging two bearings 1132 on both sides of the driven gear 1131 along its axial direction, the radial wobble of the lead screw 112 can be effectively reduced. Both bearings 1132 are preferably pressure bearings, capable of withstanding a certain axial pressure.

[0058] Please refer to Figure 2 and Figure 3 Furthermore, for the lead screw 112 adapted to the cantilever structure, the piston rod 21 has an inner cavity 210 opening along the axis A. The inner cavity 210 is used for the lead screw 112 to enter, so that when the piston rod 21 is connected to the pusher 12, the lead screw 112 is avoided. In one example, the piston rod 21 is generally cylindrical, and its inner cavity 210 opens towards the proximal end. When the proximal end of the piston rod 21 is connected to the pusher 12, the lead screw 112 is allowed to enter the inner cavity 210 to avoid the lead screw 112.

[0059] Optionally, the sealing portion 116 of the base 110 has a through hole 1101 along axis A, and the reduction gear set 113 has a connecting shaft 1134, which is fixedly connected to the driven gear 1131. The distal end of the connecting shaft 1134 passes through the through hole 1101 and is connected to the lead screw 112; the connecting shaft 1134 and the through hole 1101 form a dynamic seal. Since there may be liquid (such as leaked medicine) in the reservoir cavity 100, the dynamic seal formed by the connecting shaft 1134 and the through hole 1101 effectively reduces or avoids liquid contamination by isolating the working environment that may come into contact with liquid from the electronic components and main mechanical structural components of the portable infusion pump 1.

[0060] Optionally, the base 110 has a mounting groove 115 in which the motor 111 and the planetary reducer 114 are coaxially arranged. The shape and size of the mounting groove 115 match the motor 111 and the planetary reducer 114, thereby enclosing and limiting the motor 111 and the planetary reducer 114 to ensure installation strength. Since the output shaft of the planetary reducer 114 generally has radial and axial backlash, the torque fluctuation caused by this backlash has a significant impact on the current. To solve the problem caused by this backlash, it is preferable to install a constraint bearing 1141 on the opposite side of the output shaft of the planetary reducer 114 to constrain the backlash of the output shaft of the planetary reducer 114.

[0061] Optionally, the control module 14 is also used to collect the current of the motor 111; the control module 14 is also configured to control the motor 111 to stop operating and issue an alarm signal when the current is not less than a preset threshold.

[0062] During the injection process, after the control module 14 starts the motor 111, it synchronously collects the current I of the motor 111. Since the current I of the motor 111 has an approximately linear relationship with the pressure P of the injection circuit, the current I of the motor 111 can characterize the pressure P of the injection circuit. When the injection circuit is blocked, the pressure P will increase. When the current I of the motor 111 rises to a preset threshold Im (such as the alarm value preset by the program), that is, when I ≥ Im, the control module 14 controls the motor 111 to stop operating and issues an alarm signal. The alarm signal can be expressed through sound, light, vibration or screen display, for example.

[0063] Please refer to Figure 8a and Figure 8b In some embodiments, the preset threshold is obtained based on the relationship between the current and pressure required for the frictional force of the piston 22 of the calibrated reservoir 2 and the relationship between the current and pressure required for the frictional torque of the transmission components of the calibrated drive device 11 (such as the lead screw 112, the reduction gear set 113, and the planetary reducer 114).

[0064] Studies have found that the relationship between the current I (the actual monitored current) of motor 111 and the pressure P of the injection circuit contains certain interference terms. These interference terms include the frictional force F1 between piston 22 and cylinder 20, the frictional torque T2 of lead screw 112, the frictional torque T3 of reduction gear set 113, and the frictional torque T4 of planetary reducer 114. Specifically, since piston rod 21 is part of reservoir 2 in this embodiment, it is pushed by pusher 12 and moves along axis A, and does not contact housing 10, thus not generating frictional force relative to the injection direction. Therefore, piston rod 21 itself does not introduce additional frictional interference into the relationship between current I and pressure P. Furthermore, the frictional force F1 between piston 22 and cylinder 20 can be reduced by spraying medical silicone oil. In some embodiments, the influence of frictional force F1 on current I is controlled within 5mA to minimize the impact of piston friction in different reservoirs 2 on pressure calculation.

[0065] Further research revealed that the relationships between the current and pressure required for the frictional force F1 between the piston 22 and the cylinder 20, the frictional torque T2 of the lead screw 112, the frictional torque T3 of the reduction gear set 113, and the frictional torque T4 of the planetary reducer 114 are all approximately linear. Furthermore, the relationships between the current and pressure required for each of these frictional forces F1, T2, T3, and T4 can be pre-calibrated using different injection pressure conditions. Additionally, it is understandable that, under ideal conditions (i.e., when there are no interfering terms), the current required to establish the pressure P0 in the injection circuit can be calculated based on the driving force of the motor 111 or obtained through calibration. Figure 8a As shown.

[0066] Furthermore, based on the relationship between the current and pressure required for the calibrated frictional force F1, frictional torque T2, frictional torque T3, and frictional torque T4, a preset threshold Im is obtained. This minimizes the influence of interference on the relationship between the current I of motor 111 and the pressure P of the injection circuit. For example, in an exemplary case, 200 kPa is used as the preset blockage alarm pressure. Figure 8a and Figure 8b It can be seen that to obtain a pressure of 200 kPa, the current required based on the driving force of motor 111 is approximately 15 mA. Meanwhile, the currents required for frictional force F, frictional torque T2, frictional torque T3, and frictional torque T4 are approximately 2 mA, 4 mA, 1.5 mA, and 3.5 mA, respectively. Therefore, the total current is approximately 15 + 2 + 4 + 1.5 + 3.5 = 26 mA. Thus, the preset threshold Im can be set to 26 mA to achieve 200 kPa as the preset blocking alarm pressure.

[0067] When calculating the injection circuit pressure P using the current I of motor 111, the influence of interference terms is eliminated, and the friction between piston rod 21 and housing 10 is avoided. This reduces or avoids false alarms or delayed alarms when the circuit is blocked, thus improving safety and reliability.

[0068] In summary, the portable infusion pump and portable infusion system provided in this application include a drive device, a pusher, a non-contact progressive switch, and a control module. The drive device, under the control of the control module, drives the pusher to move along an axis in a distal or proximal direction. When the pusher moves distally, it pushes the piston rod of the reservoir. The control module is configured to, upon receiving a replacement / installation signal, control the drive device to drive the pusher proximally, and based on the correspondence between the current position of the pusher and the trigger position of the non-contact progressive switch, control the drive device to stop driving the pusher and update the pusher's initial position information. The control module is also configured to, upon receiving an injection signal, based on the current initial position information, control the drive device to drive the pusher by a driving amount corresponding to the injection signal. With this configuration, the position of the pusher can be determined without contact using the non-contact progressive switch. Each time the reservoir is replaced, the starting position information of the pusher is updated. This means that the starting position of the pusher is recalibrated every time the reservoir is replaced, so that the drive device will not accumulate position errors during long-term reuse.

[0069] It should be noted that the above embodiments can be combined with each other. The above description is only a description of preferred embodiments of this application and is not intended to limit the scope of this application in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of this application.

Claims

1. A portable infusion pump, characterized in that, include: Drive unit, pusher, non-contact progressive switch and control module; The driving device is used to drive the pusher to move along an axis toward the distal end or the proximal end under the control of the control module; when the pusher moves toward the distal end, it is used to push the piston rod of the reservoir. The control module is configured to, upon receiving a replacement installation signal, control the drive device to drive the pusher to move toward the proximal end, and based on the correspondence between the current position of the pusher and the trigger position of the non-contact progressive switch, control the drive device to stop driving the pusher and update the starting position information of the pusher. The control module is also configured to, upon receiving an injection signal, control the drive device to drive the pusher to move according to a drive amount corresponding to the injection signal, based on the current starting position information.

2. The portable infusion pump according to claim 1, characterized in that, Based on the current starting position information, the step of controlling the driving device to drive the pusher to move according to the driving amount corresponding to the injection signal includes: The control module calculates the remaining liquid volume in the reservoir based on the starting position information and the sum of the driving quantities recorded in all previous injection processes. If the remaining liquid volume is not less than the target injection volume corresponding to the current injection signal, then the target driving amount of the driving device is calculated based on the target injection volume, and the driving device is controlled to drive the pusher to move in the distal direction according to the target driving amount, and the driving amount of this injection process is recorded.

3. The portable infusion pump according to claim 2, characterized in that, If the remaining liquid volume is less than the target injection volume corresponding to the current injection signal, the control module controls the drive device to stop driving the pusher to move and issues a replacement prompt signal.

4. The portable infusion pump according to claim 1, characterized in that, The drive device includes a motor, and the control module is also used to collect the current of the motor; The control module is also configured to control the motor to stop operating and issue an alarm signal when the current is not less than a preset threshold.

5. The portable infusion pump according to claim 4, characterized in that, The preset threshold is obtained based on the relationship between the current and pressure required for the frictional force of the piston of the reservoir and the relationship between the current and pressure required for the frictional torque of the transmission component of the drive device.

6. The portable infusion pump according to claim 1, characterized in that, The driving device includes a drive motor, a lead screw, a reduction gear set, and a planetary reducer; the drive motor drives the lead screw to rotate about the axis through the planetary reducer and the reduction gear set in sequence; the pusher is threadedly connected to the lead screw and is restricted to rotate circumferentially around the lead screw.

7. The portable infusion pump according to claim 6, characterized in that, The drive device includes a base, and the reduction gear set includes a driven gear and two bearings. The two bearings are arranged along the axis on both sides of the driven gear, and the driven gear is rotatably housed in the base through the two bearings. One end of the lead screw is a free end, and the other end is coaxially connected to the driven gear.

8. The portable infusion pump according to claim 6, characterized in that, The portable infusion pump includes a housing; the drive device includes a base, the base and the housing together enclosing a reservoir cavity, the reservoir cavity being used for replacement of the reservoir therein; Both the pusher and the lead screw are housed within the reservoir cavity; The base has a through hole along the axis, and the reduction gear set has a connecting shaft that passes through the through hole and is connected to the lead screw; the connecting shaft and the through hole form a dynamic seal.

9. The portable infusion pump according to claim 1, characterized in that, The correspondence includes the positional relationship between the pusher and the non-contact progressive switch when the pusher moves towards the proximal end to the trigger position corresponding to the non-contact progressive switch.

10. A portable infusion system, characterized in that, The portable infusion pump according to any one of claims 1 to 9 further includes a reservoir; the reservoir includes a piston rod for connection with the pusher.

11. The portable infusion system according to claim 10, characterized in that, The piston rod has an inner cavity opened along the axis, the inner cavity being for the lead screw of the drive device to enter, so that when the piston rod is connected to the pusher, it avoids the lead screw.

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