Medical syringe for on-body mounting with flow detection

Abstract

In one aspect, there is provided a medical syringe for mounting onto the skin of a user for administering a dose of a liquid medicament to the user, the medical syringe comprising: a body, such that the body contains a reservoir of the liquid medicament; the cannula is used for being inserted into the skin of the user; a catheter for fluidly connecting the body and the cannula to allow the liquid medicament to be delivered to the cannula wherein the catheter comprises a tubular metal section; the temperature sensor is used for measuring the temperature of the metal section; and a CPU for collecting periodic temperature measurements from the temperature sensor to assess a change in temperature of the metal section over time. Advantageously, the invention allows a non-invasive mode of drug flow in a medical syringe on a specimen.

Description

Technical Field

[0001] This invention relates to in vivo medical syringes, and in particular to in vivo syringes with flow detection. Background Technology

[0002] In vivo medical injectors are known in the prior art. Typically, these medical injectors include a body that houses a reservoir for injectable medication. The body includes an adhesive pad for adhering to the user's skin at a target site (e.g., the user's abdomen or side). The body further includes a switch that, upon installation, actuates the injector. Actuation can cause an intubation cannula to be automatically inserted into the patient in preparation for injection. With the cannula inserted, the medication is delivered by an automated system, such as by actuating a reservoir using a motor-driven plunger.

[0003] In vivo medical syringes are primarily designed for home use. The cannula is typically concealed before use to reduce anxiety. Additionally, efforts are made to ensure optimal procedural care, as a medical professional may not be present. In vivo syringes typically have a high volumetric capacity, exceeding that delivered by standard syringes. Therefore, drug delivery time is extended to allow the user's body to receive the medication at a tolerable rate. Sufficient and appropriate drug delivery is crucial. Problems can arise because the syringe body is typically opaque, preventing visual confirmation of proper needle insertion and drug flow. Summary of the Invention

[0004] In one aspect of this application, a medical injector is provided for attachment to a user's skin to administer a dose of liquid medication to the user. The medical injector includes: a body containing a reservoir of the liquid medication; a cannula for insertion into the user's skin; a catheter fluidly connecting the body and the cannula to allow delivery of the liquid medication to the cannula, wherein the catheter includes a tubular metal segment; a temperature sensor for measuring the temperature of the metal segment; and a CPU for collecting periodic temperature measurements from the temperature sensor to assess changes in the temperature of the metal segment over time.

[0005] In another aspect of this application, a medical injector is provided for insertion onto a user's skin to administer a dose of liquid medication to the user. The medical injector includes: a body containing a reservoir of the liquid medication; a cannula for insertion into the user's skin; a catheter fluidly connecting the body and the cannula to allow delivery of the liquid medication to the cannula, wherein the catheter includes a tubular metal segment; an electrically heating element configured to generate heat and apply the heat to the metal segment; a temperature sensor isolated from the heating element for measuring the temperature of the metal segment; and a CPU for collecting periodic temperature measurements from the temperature sensor to assess changes in the temperature of the metal segment over time.

[0006] Advantageously, the present invention allows for a non-invasive mode of detecting drug flow in a medical syringe on the body.

[0007] These and other features of the invention will be better understood by studying the following detailed embodiments and accompanying drawings. Attached Figure Description

[0008] Figures 1-2 The present invention describes an in vivo medical injector available through the present invention;

[0009] Figure 3 An arrangement for detecting the flow of liquid drug in an on-body medical syringe according to the present invention is schematically depicted;

[0010] Figure 4 It is shown that by and Figure 3 A consistent arrangement of temperature measurements collected over time;

[0011] Figure 5 yes Figure 3 The arrangement has been modified to include an additional temperature sensor for contact with the user's skin and to measure the user's skin temperature; and

[0012] Figure 6 It is shown by Figure 5 A graph showing temperature measurements collected over time by an additional temperature sensor. Detailed Implementation

[0013] Referring to the accompanying drawings, a medical injector is shown, and is generally designated by reference numeral 10. The medical injector 10 is an in vivo medical injector having a body 12 and a cannula 14 for insertion into the user's skin for drug delivery. Figure 1As shown, the cannula 14 can be configured to be separate from and spaced apart from the body 12. This allows the body 12 and the cannula 14 to be separately inserted into the user's skin. The catheter 16 is configured to fluidly connect the body 12 and the cannula 14.

[0014] The body 12 includes a reservoir 18 for the liquid medication 20 to be delivered to the user by the medical syringe 10. The reservoir 18 may be in any form capable of containing the liquid medication 20, including but not limited to vials, tubes, sealed tubing, capsules, blister packs, thermoformed bodies (e.g., sealed clamshell packaging), etc. The reservoir 18 may be rigid or collapsible.

[0015] The catheter 16 is arranged to deliver liquid medication 20 from reservoir 18 to cannula 14. Liquid medication 20 can be actuated from reservoir 18 using any mode, including but not limited to advanceable plunger, compression, aspiration, etc.

[0016] The cannula 14 can be installed into the central hub 22. For example... Figure 2 As shown, the central hub 22 may be equipped with a base layer 24 having an adhesive 25 on its exposed surface for attachment to the user's skin. The central hub 14 may be formed of a polymeric material, such as a thermoplastic material. The central hub 22 may also include any actuable arrangement for automatically inserting the cannula 14 into the user's skin. This arrangement may use spring force or other driving force to move the cannula 14 from an initial concealed state (e.g., ...). Figure 1 (Illustrated in the image) actuated to a use state protruding from the central seat 22 (where the cannula is inserted into the user's skin).

[0017] Alternatively, the cannula 14 can be configured for manual insertion into the user's skin, for example, in the form of a butterfly needle.

[0018] Furthermore, alternatively, the cannula 14, together with the central hub 22, can be located within the body 12. Using this arrangement, the medical syringe 10 will be a single component for insertion into the user's skin, rather than separately inserting the body 12 and the cannula 14 (central hub 22, if used) into the user's skin. Here, the cannula 14 can also be configured to automatically insert into the patient's skin, for example, in response to a driving force (e.g., spring force). The central hub 22 can be a support for the cannula 14 and does not need to be adhered to the patient's skin, especially when the cannula 14 is located within the body 12.

[0019] The catheter 16 may be flexible, for example, formed of a flexible polymer and / or elastomeric material. This allows the catheter 16 to shift or deform in response to movement of the medical syringe 10 during transport, storage, and injection preparation. The catheter 16 may be formed of a rigid material (e.g., metal, rigid plastic, etc.), but this is less preferred. The catheter 16 may be formed of polymer and / or elastomeric materials, including but not limited to medical-grade polyvinyl chloride (PVC), polyurethane, or equivalents. The catheter 16 is tubular, having a lumen 26 defined therethrough for the passage of liquid medication 20.

[0020] The present invention provides an arrangement for detecting the flow of a liquid drug through conduit 16. This detection is not a measurement, as the flow rate is deterministic. Rather, the invention aims to determine whether flow actually exists through conduit 16. In short, the invention provides a binary indication of the presence of flow in identifying whether flow exists. The level or rate of flow is not determined. This avoids the complexity of flow rate measurement arrangements using pressure reduction (e.g., a venturi tube), in-tube displaceable elements (e.g., an impeller), etc.

[0021] It should also be noted that the present invention uses a non-invasive mode of defined flow. In this way, the flow is completely contained within the catheter 16 without any foreign elements directly contacting the liquid drug 20. This maintains sterility.

[0022] In one arrangement, a tubular metal segment 28 may be included within the conduit 16. Preferably, the metal segment 28 has an inner lumen 30 having a generally constant cross-section. Additionally, it is preferred that the cross-section of the inner lumen 30 matches the cross-section of the inner lumen 26, such that the metal segment 28 does not impede flow through the inner lumen 26 or otherwise adversely affect it. The metal segment 28 may be positioned along the conduit 16 such that the non-metallic portions of the conduit 16 are located on either side of the metal segment 28. A portion of the conduit 16 may be located within or defined by the pivot 22, particularly the downstream portion of the conduit 16. Further preferably, the outer diameter of the metal segment 28 matches the outer diameter of the conduit 16, providing a single profile along the entire length of the conduit 16. The metal segment 28 may be located outside the body 12 (e.g., between the body 12 and the pivot 22) or inside the body 12 (e.g., when the cannula is located inside the body 12).

[0023] The metal section 28 can be connected to the adjacent portion of the conduit 16 using any technique that allows the element to be connected to the defined liquid-tight seal. Welding (e.g., metal / plastic welding) and / or adhesion can be used.

[0024] like Figure 3As shown, temperature sensor 32 is positioned to measure the temperature of metal section 28. Temperature sensor 32 can acquire a temperature reading of the outer surface of metal section 28. Temperature sensor 32 is preferably an electrical element that provides a voltage or current output representing a temperature reading. Temperature sensor 32 can be one or more of the following: a thermistor; a thermocouple; a semiconductor-based temperature sensor; a resistive temperature detector (RTD); and an infrared (IR) temperature sensor.

[0025] Temperature sensor 32 acquires periodic readings, starting with at least one initial baseline reading prior to the actuation of flow of liquid drug 20. The initial baseline reading provides an indication of temperature at which no flow is passing through conduit 16. Upon actuation, flow should be initiated to pass through conduit 16. As liquid drug 20 moves through conduit 16 and, in particular, through metal section 28, the liquid drug 20 causes heat removal as it flows through metal section 28, thereby causing a decrease in temperature. A computer processing unit (CPU) 34 is provided, electrically coupled to temperature sensor 32, and collects the temperature measurements taken by temperature sensor 32. With temperature sensor 32 acquiring periodic readings over time, the relationship between temperature and time can be evaluated, such as… Figure 4 As shown. For example, as Figure 4 As shown between T = 60 and T = 180, the temperature exhibits a steady decrease. This indicates the removal of heat energy by flowing the liquid drug 20. The temperature can tend to plateau, representing the flow state when the temperature reaches a steady state. However, an increase in temperature can indicate a lack of flow. This can be detected by the upward inflection point of the temperature versus time curve. Flow can be monitored for temperature increases, particularly above a predetermined threshold.

[0026] Preferably, the metal section 28 is positioned immediately adjacent to the cannula 14 (and thus immediately adjacent to the central seat 22). This allows for monitoring of fluid flow near the cannula 14, thus providing better indication of proper operation. If the metal section 28 is positioned further upstream along the catheter 16 away from the cannula 14, obstructions or kinks in the catheter 16 may not be identifiable.

[0027] In cases where the medical injector 10 includes a catheter 16 at room temperature, it may be difficult to detect temperature changes unless a high-end temperature sensor with a high level of sensitivity is used. Preferably, the catheter 16 is at a temperature above standard room temperature to better allow for the detection of temperature changes while monitoring flow. Body heat from the user can provide an elevated temperature. Advantageously, heat can be applied because the medical injector 10 is attached to the user's skin. Alternatively or additionally, refer to Figure 3An electric heating element 36 (e.g., a resistor) can be used to generate heat and apply it to the metal section 28. Preferably, the electric heating element 36 applies heat before the actuation of the flow of the liquid drug 20, wherein the temperature is measured by a temperature sensor 32. This allows a baseline reading to be obtained before the liquid drug 20 flows.

[0028] Temperature sensor 32 and electric heating element 36 can be mounted on a common substrate 38, which can be a printed circuit board or the like. To avoid misreading, it is preferable that temperature sensor 32 is isolated from electric heating element 36 (e.g., thermally isolated). This prevents heat energy from electric heating element 26 from directly and adversely affecting temperature sensor 32. Substrate 38 can be attached to body 12 or central base 22.

[0029] The power for the temperature sensor 32 and the electric heating element 36 can be supplied from a power unit associated with the body 12 and / or, for example, a power source locally located on the central seat 22 (including on the substrate 38).

[0030] CPU 34 may be equipped with memory for storing temperature readings. Additionally, a transmitter (e.g., a wireless transmitter) may be provided for transmitting the collected data to a remote location, for example, to verify appropriate dose administration. The transmitter may be mounted on body 12 or hub 22. CPU 34 may be located on body 12 or hub 22.

[0031] A second temperature sensor 40 may be provided, positioned in direct contact with the user's skin to measure the user's skin temperature while the medical syringe 10 is attached to the user's skin. Periodic temperature monitoring by the second temperature sensor 40 can provide an indication of the degree to which the medical syringe 10 or a portion thereof is properly attached to the user's skin. This is advantageous because the flow of the drug product can be stopped midway through injection if it is sensed that the medical syringe 10 is no longer in proper contact with the patient's skin during injection. The CPU 34 may be electrically coupled to the second temperature sensor 40 to collect temperature readings from the second temperature sensor 40 for evaluation. With the temperature sensor 40 acquiring periodic readings over time, the relationship between temperature and time can be evaluated, such as… Figure 6 As shown. Figure 6 As shown between T = 60 and T = 180, the temperature shows a steady increase. If the temperature reading indicates a decrease in temperature, this may indicate partial or complete separation from the user's skin. The temperature can tend to plateau, representing the skin's temperature. Additionally, some temperature variation is expected due to the integrity of skin contact and the inherent changes in skin temperature. Figure 6As shown, the temperature band defined by a curve representing the high end of the temperature range (highest T) and a second curve representing the low end of the temperature range (lowest T) can be monitored over time. It is noteworthy that the two curves have similar shapes. The curves can be monitored by targeting similar inflection points within the two curves.

[0032] like Figure 5 As shown, the second temperature sensor 40 can be disposed on the substrate 38, but on the side opposite to the temperature sensor 32 and the electric heating element 36. This arrangement allows the second temperature sensor 40 to monitor the adhesion of the central seat 22 (in the case that it is provided separately from the body 12). This provides a specific indication of the adhesion of the central seat 22, and thus provides proper insertion of the cannula 14 into the user's skin.

[0033] Alternatively, an additional temperature sensor can be provided for the body 12, which can be monitored independently in a manner similar to the second temperature sensor 40. This allows for monitoring of the adhesion of the body 12 (especially when mounted separately from the hub 22). The CPU 34 can be electrically coupled to any additional temperature sensor in a similar manner.

[0034] Similar to temperature sensor 32, the second temperature sensor 40 and any additional temperature sensors can be one or more of the following: a thermistor; a thermocouple; a semiconductor-based temperature sensor; and a resistive temperature detector (RTD). Data collected from these temperature sensors can be stored and transmitted in a manner similar to that discussed above. Power can also be provided in a similar manner.

Claims

1. A medical syringe for attachment to a user's skin to administer a dose of liquid medication to the user, the medical syringe comprising: The body, therefore the body contains a reservoir for the liquid drug; A cannula, the cannula being inserted into the user's skin; A catheter for fluidly connecting the body and the cannula to allow the liquid medication to be delivered to the cannula, wherein the catheter includes a tubular metal section; Temperature sensor, the temperature sensor being used to measure the temperature of the metal section; and The CPU is used to collect periodic temperature measurements from the temperature sensor to assess the temperature change of the metal section over time.

2. The medical syringe according to claim 1, wherein, The temperature sensor is one or more of the following: a thermistor; a thermocouple; a semiconductor-based temperature sensor; a resistive temperature detector (RTD); and an infrared (IR) temperature sensor.

3. The medical syringe according to claim 1, wherein, The metal section is positioned adjacent to the insertion cannula.

4. The medical syringe of claim 1, further comprising an actuator for initiating delivery of the liquid medication from the reservoir into the catheter for delivery to the cannula.

5. The medical syringe according to claim 4, wherein, Before initiating the delivery of the liquid drug, the temperature sensor measures the temperature of the metal section.

6. The medical syringe of claim 1, further comprising a second temperature sensor for direct contact with the user's skin to measure the temperature of the user's skin when the medical syringe is attached to the user's skin.

7. The medical syringe according to claim 6, wherein, The CPU collects periodic temperature measurements from the second temperature sensor.

8. The medical syringe according to claim 6, wherein, The cannula is installed into a central hub, which is separate from and spaced apart from the body, and wherein the second temperature sensor is associated with the central hub.

9. The medical syringe according to claim 1, wherein, The metal section has an overall unchanged internal cross-section.

10. The medical syringe according to claim 1, wherein, The cannula is installed into a central hub, which is separate from and spaced apart from the body.

11. The medical syringe according to claim 10, wherein, The metal section is located along the conduit between the body and the central seat.

12. The medical syringe according to claim 11, wherein, The metal section is positioned adjacent to the central seat.

13. The medical syringe according to claim 1, wherein, The portion of the conduit adjacent to the metal section is non-metallic.

14. A medical syringe for attachment to a user's skin for administering a dose of liquid medication to the user, the medical syringe comprising: The body, therefore the body contains a reservoir for the liquid drug; A cannula, the cannula being inserted into the user's skin; A catheter for fluidly connecting the body and the cannula to allow the liquid medication to be delivered to the cannula, wherein the catheter includes a tubular metal section; An electric heating element configured to generate heat and apply the heat to the metal segment; A temperature sensor isolated from the heating element, the temperature sensor being used to measure the temperature of the metal section; and The CPU is used to collect periodic temperature measurements from the temperature sensor to assess the temperature change of the metal section over time.

15. The medical syringe according to claim 14, wherein, The temperature sensor is one or more of the following: a thermistor; a thermocouple; a semiconductor-based temperature sensor; a resistive temperature detector (RTD); and an infrared (IR) temperature sensor.

16. The medical syringe of claim 14, wherein, The heating element and the temperature sensor are mounted on a common substrate.

17. The medical syringe according to claim 14, wherein, The metal section is positioned adjacent to the insertion cannula.

18. The medical syringe according to claim 14, wherein, The heating element is a resistor.

19. The medical syringe of claim 14, further comprising an actuator for initiating delivery of the liquid medication from the reservoir into the catheter for delivery to the cannula.

20. The medical syringe according to claim 19, wherein, Before initiating the delivery of the liquid drug, the heating element applies heat to the metal section.

21. The medical syringe according to claim 20, wherein, Before initiating the delivery of the liquid drug, the temperature sensor measures the temperature of the metal section.

22. The medical syringe of claim 14, further comprising a second temperature sensor for direct contact with the user's skin to measure the temperature of the user's skin when the medical syringe is attached to the user's skin.

23. The medical syringe according to claim 22, wherein, The CPU collects periodic temperature measurements from the second temperature sensor.

24. The medical syringe according to claim 22, wherein, The cannula is installed into a central hub, which is separate from and spaced apart from the body, and wherein the second temperature sensor is associated with the central hub.

25. The medical syringe according to claim 14, wherein, The metal section has an overall unchanged internal cross-section.

26. The medical syringe according to claim 14, wherein, The cannula is installed into a central hub, which is separate from and spaced apart from the body.

27. The medical syringe according to claim 26, wherein, The metal section is located along the conduit between the body and the central seat.

28. The medical syringe according to claim 27, wherein, The metal section is positioned adjacent to the central seat.

29. The medical syringe according to claim 14, wherein, The portion of the conduit adjacent to the metal section is non-metallic.

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