System for detecting the force applied during an injection - Patent application

Abstract

To solve the problems in which: current injection systems do not provide a user with information on appropriate application force; and mechanical relationships between a pen needle hub, application force and required injection depth exist necessitating this type of information.SOLUTION: A medical device (100) includes an insulin pen (102), a pen needle (104), and a force sensor (106). The device also includes a microprocessor (206) to receive a signal from the force sensor (106). Audible and / or visual indicators (218, 220) provide feedback to a user to encourage a proper injection technique.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] Disclosed herein are systems and methods for detecting and indicating the force applied to the skin surface during medication injection to promote proper injection technique and accurate needle insertion depth. Alternative embodiments incorporate additional sensors to capture the force applied to the pen system injector button during dose delivery. [Background technology]

[0002] The majority of patients managing diabetes utilize syringe or pen devices for insulin administration and rely on proper injection technique and device performance for consistent delivery to subcutaneous tissue. Improper technique causing discomfort / pain can impact treatment adherence. Poor technique resulting in incomplete delivery of the full dose (leakage), intradermal (shallow) or intramuscular (deep) delivery, and injection into adipose tissue leads to inconsistent glycemic control and contributes to short- and long-term diabetes-related complications. Self-injection instruction is often only provided at the beginning of treatment. As a result, skill development is highly patient-dependent and may result in suboptimal methods due to psychological or physical barriers. Parents and caregivers administering the injection are at a distinct disadvantage as direct sensory feedback is not possible. Summary of the Invention [Problem to be solved by the invention]

[0003] Current injection systems do not provide the user with information regarding the appropriate applied force, and there exists a mechanical relationship between the pen needle hub, the applied force, and the desired injection depth, making such information necessary. [Means for solving the problem]

[0004] The present invention provides diabetic and other medical educators, caregivers, and patients with a practical tool for developing and maintaining proper injection technique to promote consistent needle depth placement within target tissue. The system according to the exemplary embodiment further provides a meaningful way to develop optimized injection devices (pens, autoinjectors, pen needles, syringes) by measuring and understanding the insertion force / force applied. The present invention provides a clinically useful tool to measure the force applied and equate it with system function, patient acceptability, preference, and other human factors. Finally, by using a feedback control loop, the present invention can promote proper use by either signaling (e.g., by a light, sound, or vibration indicator) when the appropriate force is being applied to the device, or by creating a lockout that prevents use until the system force is within the appropriate range.

[0005] Embodiments of the present invention will now be described with reference to the accompanying drawings. [Brief description of the drawings]

[0006] [Figure 1A] FIG. 1 is an exploded view of a first embodiment of the present invention. [Figure 1B] FIG. 1B is a detailed view of the force sensor on the pen needle hub of FIG. 1A. [Diagram 2] 2 is a block diagram of a signal processing circuit according to an exemplary embodiment of the present invention. [Diagram 3] FIG. 13 shows another embodiment of the invention with two force sensors. [Figure 4A] 1 is a force over time graph showing the force applied to the thumb and the skin. [Figure 4B] 1 is a force over time graph showing the force applied to the thumb and the skin. [Figure 4C] 1 is a force over time graph showing the force applied to the thumb and the skin. [Figure 4D]1 is a force over time graph showing the force applied to the thumb and the skin. [Figure 4E] 1 is a force over time graph showing the force applied to the thumb and the skin. [Figure 4F] 1 is a force over time graph showing the force applied to the thumb and the skin. [Figure 4G] 1 is a force over time graph showing the force applied to the thumb and the skin. [Figure 4H] 1 is a force over time graph showing the force applied to the thumb and the skin. [Figure 4I] 1 is a force over time graph showing the force applied to the thumb and the skin. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Throughout the drawings, like reference numerals should be understood to represent like elements, features, and structures.

[0008] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. The embodiments described herein are merely exemplary and serve to illustrate to those skilled in the art how to make and use embodiments of the invention, but it should be recognized that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the invention.

[0009] As illustrated in Figures 1A and 1B, a first embodiment of the present invention is a device 100 including an insulin pen 102 with a pen needle 104 and a force sensor 106. The force sensor 106 is preferably located on a hub surface 108 of the pen needle 104. When the insulin pen is used, the pen needle 104 is pressed against a skin surface and the force sensor 106 converts the change in physical stimulus into an electrical signal. The electrical signal is preferably conditioned and converted, such as by a signal conditioning circuit, into a mechanical quantity such as a force value and transferred to a microcontroller, where the force value may serve as an input to an algorithm or process.

[0010] FIG. 2 illustrates an exemplary block diagram of a processing circuit according to an embodiment of the present invention. The processing circuit is preferably physically incorporated into the device 100 illustrated in FIG. 1A and FIG. 1B, although one skilled in the art would readily recognize that one or more of the components of the processing circuit described herein may be located in a separate device. The processing circuit 200 of FIG. 2 preferably includes the force sensor 106, a signal amplifier 202 for amplifying the raw signal received from the force sensor 106, an analog-to-digital converter 204, and a microcontroller 206 that receives a converted digital signal representing the force value from the force sensor. The processing circuit also preferably includes a power supply 208, preferably including a DC-DC converter 210 or the like for providing power to the microcontroller 206 from a coin battery. The power supply 208 also preferably includes a rechargeable battery (not shown), such as a LiPO battery, as well as an associated voltage regulator 212 and charge management controller 214. The processing circuitry also preferably includes a USB port 216, or the like, for connecting the processing circuitry 200 to other devices and for charging a rechargeable battery. The processing circuitry 200 also preferably includes visual indicators, such as an LED indicator 218, and an audible indicator 220, for outputting indications to a user.

[0011] The microcontroller 206 preferably includes or has associated therewith a memory 222 containing program instructions for execution. The program instructions may advantageously be provided to follow a set of rules based on the data received from the force sensor and may also be provided to provide feedback to the caregiver via visual and / or audible indications based on the measured applied force.

[0012] A second exemplary embodiment is illustrated in FIG. 3. The second embodiment is similar to the first embodiment, except that the device 300 includes two load sensors instead of one. This embodiment includes an adapter assembly 300 that can be incorporated onto the end of any standard insulin pen 302. The assembly 300 includes a force sensor 304, such as a donut-shaped load cell, a sensor housing 306, and a transfer needle assembly 308. The adapter assembly 300 preferably screws onto a standard insulin pen and provides a connection 310 for a pen needle 312. The force sensor 304 measures the force applied to the skin surface during the injection procedure. The device 300 also includes a load sensor 314 that is associated with the thumb button 308 and measures the force applied to deliver medication through the pen system. Processing circuitry and power may be incorporated into the adapter assembly, or connections may be provided to an external device that houses those components. In this way, injection force can be measured and feedback can be provided to the user of any standard insulin pen.

[0013] 4A-I illustrate data recorded from a device according to a second embodiment. As shown, two load sensors are incorporated into the device, one on the thumb button and one in the connector adapter. The force measured by the two sensors over time is plotted in the figure. As shown, for this particular injection, the force applied to the skin is measured instantly and held at a semi-stable level, followed by a measurement of the thumb force required to deliver the injectate from the pen system to the injection site. Once fluid delivery is complete, the applied thumb force is stopped. The device is held on the skin surface for 5-10 seconds after fluid delivery to minimize leakage from the injection site. At the end of the injection procedure, the insulin pen is withdrawn from the user.

[0014] As will be appreciated by those skilled in the art, by recording the force present on the insulin pen or components thereof during an injection, an analysis of the injection can be performed and feedback can be derived and provided to the user. For example, such data would reveal that the user is not using enough force or is not holding the insulin pen at the injection site for a long enough duration after the thumb button is pressed.

[0015] A preferred embodiment of the device has a force sensor integrated into or on the pen needle hub surface. Electrical connections are provided within the pen needle hub to provide power to the force sensor and a force signal is acquired for further processing. Processing circuitry and power supply are preferably provided inside the pen system body.

[0016] A second embodiment includes a force sensor integrated into or on the pen needle hub, with flex circuit leads configured to connect to a separate housing external to the insulin pen. The power supply and processing circuitry are preferably located in the external housing. The external housing is configured to fit onto the insulin pen as an add-on device.

[0017] As will be appreciated by one of ordinary skill in the art, any of the embodiments described herein may incorporate circuit components that enable data transfer over wired or wireless media to a durable medium such as a CPU, tablet, phone, and / or watch with associated software applications for data visualization and storage.

[0018] Additionally, although embodiments of the present invention have been described in relation to a pen needle device, those skilled in the art will recognize that any suitable injection or drug delivery system that requires direct contact with the skin or other physiological surface can utilize the principles and features outlined herein.

[0019] Finally, those skilled in the art will recognize that changes to the disclosed embodiments are possible without departing from the scope of the invention as defined in the claims and their equivalents, and that features of different embodiments and claims may be combined with each other unless they are mutually inconsistent.

Claims

1. an insulin pen having a pen needle attached thereto; a force sensor disposed on a hub surface of the pen needle, the force sensor measuring the force applied to a skin surface during an injection procedure; a microcontroller that receives signals from the force sensor and records force data over time during an injection; at least one of an audible indicator and a visual indicator controlled by the microcontroller; wherein the microcontroller activates the audible or visual indicator based on data received from a force sensor according to a set of rules.

2. 10. The medical device of claim 1, further comprising an amplifier for amplifying an analog signal of the force sensor and an analog-to-digital converter for converting the amplified signal to digital.

3. The medical device of claim 1 , further comprising a power supply that provides power to the microcontroller.

4. 4. The medical device of claim 3, further comprising a voltage regulator for controlling power from the power source and a charge management controller for controlling charging of a battery.

5. The medical device of claim 4 , wherein the battery is a rechargeable battery.

6. 10. The medical device of claim 1, further comprising a USB port for connecting the microcontroller to an external device and for receiving power to charge a battery.

7. 10. The medical device of claim 1, further comprising a memory containing program instructions for following rules based on data received from the force sensor and for providing feedback via the at least one indicator based on the applied force measured by the force sensor.

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