(141 days)
The InPen is a home-use reusable pen injector for single-patient use by people with diabetes age 12 and older for the self-injection of a desired dose of insulin. The pen injector is compatible with Lilly Humalog® U-100 3.0 mL cartridges of insulin and single-use detachable and disposable pen needles (not included). The pen injector allows the user to dial the desired dose from 0.5 to 30 units in one-half (1/2) unit increments.
The InPen is a home-use reusable pen injector for single-patient use by people with diabetes age 12 and older for the self-injection of a desired dose of insulin. The pen injector is compatible with Novo Nordisk Novolog® U-100 3.0 mL cartridges of insulin and single-use detachable and disposable pen needles (not included). The pen injector allows the user to dial the desired dose from 0.5 to 30 units in one-half (1/2) unit increments.
The InPen dose calculator, a component of the InPen app, is indicated for the management of diabetes by people with diabetes age 12 and older by calculating an insulin dose or carbohydrate intake based on user entered data. Prior to use, a healthcare professional must provide the patient-specific target blood glucose, insulin-to-carbohydrate ratio, and insulin sensitivity parameters to be programmed into the software.
The InPen System consists of a manually-controlled pen injector and an app containing a logbook and a dose (bolus) calculator.
The InPen is a manual pen injector containing a non-replaceable battery and electronics to communicate via Bluetooth® with the app on an iOS® mobile device. The intended dose is manually set by the user by rotating a dose knob. The insulin is injected by manually depressing the dose knob which causes the piston in the insulin cartridge to expel the intended dose. The InPen is provided in two different models for compatibility with the available U-100 insulin cartridges, i.e. Humalog® and Novolog®. The device is provided with Instructions For Use and a Quick Start Guide. The device is used with sterile needles and U-100 insulin cartridges (supplied separately).
The app is designed to manage the wireless transfer of insulin dose data from the InPen, log insulin dose data, and provide a dose calculator to aid mealtime insulin dose calculations. The insulin dose calculations provided by the app are meant for patients undergoing multiple daily injection (MDI) therapy. The InPen app is not intended to serve as an accessory to an insulin pump.
Here's an analysis of the acceptance criteria and supporting study for the InPen System, based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly present a direct table of "acceptance criteria" alongside "reported device performance" for each specific requirement in the way a formal test report might. However, it states that the device was tested against specific standards and "met the acceptance criteria." I will synthesize this information from the "Performance Data" section.
| Acceptance Criterion (Standard or Requirement) | Reported Device Performance |
|---|---|
| Biocompatibility: | |
| ISO 10993-1 (Cytotoxicity, Sensitization, Irritation/Intracutaneous Reactivity) | InPen System is considered biocompatible and acceptable for use. |
| Electromagnetic Compatibility & Electrical Safety: | |
| IEC 60601-1 (Basic Safety & Essential Performance) | Complies with requirements. |
| IEC 60601-1-2 (EMC) | Complies with requirements. |
| IEC 60601-1-11 (Home Healthcare Environment) | Complies with requirements. |
| Software: | |
| FDA Guidance for Industry and FDA Staff, "Guidance for the Content of Premarket Submissions for Software Contained in Medical Devices" (Software Level of Concern: Major) | Software verification and validation testing conducted, documentation provided. |
| Bench Testing (Pen Injector): | |
| ISO 11608-1 (Needle-Based Injection Systems) | InPen System functioned as intended and met the acceptance criteria in all instances (general design, mechanical characterization, dose accuracy). |
| ISO 11608-4 (Pen-Injectors For Medical Use) | Requirements met where appropriate due to modifications for electronic/electromechanical pen-injectors. |
| Clinical Evidence (User Interface/Human Factors): | |
| Hazard analysis according to ISO 14971 | Hazard analysis completed. |
| Human Factors Summative Study (absence of critical errors leading to hazard) | After self-training, patients were able to use the InPen System without making critical errors that could lead to a hazard. No new use-related hazards identified. |
| Dose Calculator Functionality: | |
| Standard approach using HCP-specified insulin-to-carbohydrate ratio and insulin sensitivity factors. | Uses standard approach. |
| Consideration for insulin on-board based on specific published study. | Includes consideration for insulin on-board based on Mudaliar, et al. (1999) study. |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: The document mentions a "comprehensive Human Factors Summative Study" involving "patients with sufficient diabetes knowledge." However, it does not specify the exact sample size for this study.
- Data Provenance: The document does not explicitly state the country of origin for the data used in the Human Factors Summative Study. It is implied to be a prospective study as it involved patients completing tasks with the InPen System.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
The document does not provide information on the number or qualifications of experts used to establish ground truth for the clinical (Human Factors Summative) test set. The assessment appears to be based on observed user performance and identification of critical errors, rather than expert-adjudicated diagnostic "ground truth."
4. Adjudication Method for the Test Set
The document does not specify an adjudication method (e.g., 2+1, 3+1, none) for the Human Factors Summative Study. The focus was on identifying critical errors during user interaction, which would likely be observed and documented by study facilitators/observers, rather than requiring expert adjudication of different interpretations.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This type of study is typically used for diagnostic devices involving humans interpreting results (e.g., radiologists reading images) and comparing performance with and without AI assistance. The InPen System is a pen injector with a dose calculator, and its evaluation focused on functionality, safety, and human factors, not on improving human reader performance in a diagnostic context.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
Yes, a form of standalone performance was implicitly done for the dose calculator component. The document states:
- "The dose calculator uses the standard approach using healthcare provider specified insulin-to-carbohydrate ratio and insulin sensitivity factors for making calculations."
- "In addition, the calculator includes a consideration for insulin on-board based on the published study by Mudaliar, et.al. (1999) for the duration of insulin action."
This indicates that the algorithm's calculation logic was assessed against established medical standards and a specific published clinical model, which represents a standalone evaluation of its computational accuracy and adherence to a defined medical algorithm.
7. The Type of Ground Truth Used
- For biocompatibility, EMC, electrical safety, and bench testing, the ground truth was adherence to established national and international standards (ISO, IEC).
- For the software verification and validation, the ground truth was adherence to FDA guidance documents for software in medical devices.
- For the Human Factors Summative Study, the ground truth was the absence of "critical errors that could lead to a hazard" during patient use, as determined by observation during the study.
- For the dose calculator, the ground truth for its logic was based on established medical practice/formulas (HCP-specified parameters) and a published clinical study/model (Mudaliar, et al. 1999 for insulin on-board).
8. The Sample Size for the Training Set
The document does not explicitly mention a training set sample size. The InPen System as described is a hardware device (pen injector) with a software component (app/dose calculator). The "training" for such devices typically refers to the data used during the development of the algorithms (firmware for the pen, logic for the app). This information is generally part of the internal development process and not usually reported as a "sample size" in FDA submission summaries unless a specific machine learning model with a distinct training phase is being described. Given the nature of the device (a calculator using established formulas rather than a predictive AI model trained on patient data), a traditional "training set" for an AI model may not be applicable.
9. How the Ground Truth for the Training Set Was Established
As noted above, a distinct "training set" in the context of an AI/ML model for diagnostic or predictive purposes is not explicitly described. For the algorithmic logic of the dose calculator, the ground truth was established by:
- Medical consensus/standards: The use of "healthcare provider specified insulin-to-carbohydrate ratio, and insulin sensitivity parameters." These are standard, well-accepted medical formulas.
- Published clinical research: The "consideration for insulin on-board based on the published study by Mudaliar, et.al. (1999)." This study's findings served as the basis for incorporating this aspect into the calculator's logic.
§ 880.5860 Piston syringe.
(a)
Identification. A piston syringe is a device intended for medical purposes that consists of a calibrated hollow barrel and a movable plunger. At one end of the barrel there is a male connector (nozzle) for fitting the female connector (hub) of a hypodermic single lumen needle. The device is used to inject fluids into, or withdraw fluids from, the body.(b)
Classification. Class II (performance standards).