Question

In the insulin pump system, the user has to change the needle and insulin supply at regular intervals and may also change the maximum single dose and the maximum daily dose that may be administered. Suggest three user errors that might occur and propose safety requirements that would avoid these errors resulting in an accident.

Short answer

User errors: wrong needle placement, missed insulin refill, incorrect dose setting. Safety: force-feedback for needles, alert for low insulin, confirmation for dose changes.

Step-by-step solution

Understanding the Context

We need to identify potential errors related to insulin pump usage, specifically around needle, insulin changes, and dose settings. These errors could stem from incorrect replacements or improper dose settings. Understanding this context allows us to identify where errors could occur.

Identifying User Errors

List three user errors that may occur: 1. Incorrectly changing or placing the needle, which might not deliver insulin properly. 2. Failing to replace the insulin supply regularly, potentially leading to depletion and missed doses. 3. Setting incorrect values for the maximum single dose or maximum daily dose, risking overdosing or underdosing.

Proposing Safety Requirement for Needle Replacement

To avoid errors in needle replacement, introduce a force-feedback mechanism that ensures the needle is correctly attached and operational. This mechanism could alert the user if the needle is improperly installed or if it is not functioning.

Proposing Safety Requirement for Insulin Supply Replacement

Implement an automated alert system that notifies the user when the insulin supply is running low. The system could track usage patterns to predict when insulin will run out and ensure timely reminders are given.

Proposing Safety Requirement for Dose Settings

Incorporate a dose setting lock that requires user confirmation via an alert before changes can be made to the maximum single or daily doses. This ensures that any intended changes are reviewed and prevents accidental input changes.

Key concepts

User Error Prevention

Insulin pumps are vital devices for people managing diabetes, but they can be prone to user errors. Preventing these errors is crucial to ensure proper insulin delivery. The most common mistakes occur during needle placement, insulin supply changes, and adjusting dose settings. Proper preventative measures can reduce these errors significantly:

• Needle Placement: Incorrectly inserted needles can prevent insulin from being delivered effectively. To prevent this, a force-feedback mechanism can be introduced to alert users if a needle is improperly attached or not functioning as expected.


• Insulin Supply: Users may forget to replace the insulin supply. An automated alert system that notifies the user when the insulin is running low is beneficial. This notification helps prevent the depletion of insulin and missed doses.


• Dose Settings: Incorrect dose settings can lead to overdosing or underdosing. Implementing a dose setting lock, where changes need confirmation, can help review these changes and prevent accidental errors.

Safety Requirements

For insulin pumps to operate safely, specific safety requirements must be in place. These requirements serve as a safeguard against user errors and malfunctions, ensuring the user receives the correct insulin dose and the device operates smoothly. Key safety requirements include:

• Force-Feedback Mechanism: This ensures the needle is correctly placed by providing sensory feedback. In case of an incorrect placement, it alerts the user to adjust the needle, ensuring proper insulin delivery.


• Automated Alert System: Essential for managing insulin supply, this system tracks the user's insulin usage patterns. It predicts when insulin might run out and sends timely replacement reminders, avoiding any risk of insulin depletion.


• Dose Confirmation Alerts: Once users attempt to change dose settings, a confirmation alert should be prompted. This system requires users to review and confirm their changes, preventing any accidental and potentially harmful dose adjustments.

Insulin Pump System

An insulin pump system is a small device that continuously delivers insulin to the body, mimicking the insulin release of a healthy pancreas. The system is designed to improve blood sugar management and offer greater freedom compared to traditional injections. Key components of this system include:

• Pump Mechanism: This is the core unit that houses the insulin reservoir and controls insulin delivery according to pre-set programs.


• Needle or Cannula: A small tube or needle that is inserted under the skin to deliver insulin. Ensuring proper placement is vital for the effective functioning of the pump.


• Control Interface: This allows users to adjust doses, check insulin levels, and receive alerts. Advanced systems include user-friendly digital interfaces to enhance the user experience and reduce errors.

A well-designed insulin pump system should prioritize user safety by integrating mechanisms that prevent errors and ensure continuous, accurate insulin delivery.