Designing Small Housings and Enclosures for Medical Devices

Designing small enclosures for medical devices requires a balance of compact design, durability, and regulatory compliance. Whether for handheld diagnostic tools or life-supporting systems, these housings must be lightweight, ergonomic, and suitable for use in clinical environments.

D&M Plastics delivers precision medical plastic injection molding services, producing high-quality enclosures and components while meeting strict healthcare standards.

Material Selection Considerations

Selecting the appropriate thermoplastic for small medical enclosures is necessary to provide safety, performance, and compliance. Be sure to consider the following factors:

• Biocompatibility. Materials must comply with ISO 10993 or USP Class VI standards to ensure they are safe for contact with the human body.
• Chemical Resistance. Selected plastics should resist degradation from repeated exposure to medical disinfectants and cleaning agents.
• Strength and Impact Resistance. Enclosures must withstand routine handling, including accidental drops and mechanical stress, during use or transport.
• Sterilization Compatibility. Materials must support sterilization methods such as autoclaving or gamma radiation without degrading or deforming.

Common Materials

Below is a comparison of commonly used thermoplastics for medical enclosures, selected for their performance, safety, and suitability in clinical environments:

For more detailed information on material and compliance requirements, refer to our ISO certifications.

Potential Applications & Functions

Small plastic enclosures are used across a wide range of medical devices to protect internal components, support usability, and meet strict hygiene and safety standards. Common applications include:

• Insulin pump enclosures. Used in portable diabetes management devices to protect electronics, screens, and buttons. Typically made from lightweight, impact-resistant ABS or polycarbonate.
• Patient monitoring device casings. House sensors, displays, and communication hardware in devices like ECG machines and pulse oximeters. Often designed for handheld use and molded from PC or PC/ABS blends with EMI shielding.
• Hearing aid shells. Enclose miniature electronics and microphones in a compact, comfortable form. Commonly custom-molded from acrylic or nylon.
• Handheld diagnostic device housings. Found in glucose meters, digital thermometers, and portable ultrasound tools. Made from impact-resistant plastics, sometimes with rubber overmolding for grip.
• Infusion pump enclosures. Protect mechanical pump systems and digital controls in hospital settings. Often feature tamper-proof designs and are molded from polycarbonate or PC blends with clear display windows.
• Surgical tool controllers. Used in electronic handpieces like cautery pens or surgical drills. Designed for ergonomic grip, fluid protection, and sterilization compatibility using PPSU, PEEK, or medical-grade nylon.
• Wearable health monitors. Used in fitness or ECG patches that continuously track vitals. Require flexible, biocompatible housings made from TPU or soft-touch silicone.
• Smart inhaler housings. Enclose sensors and Bluetooth modules in connected asthma or COPD inhalers without obstructing airflow. Typically made from PC or ABS, sometimes with antimicrobial coatings.

Design for Functionality and Usability

Key design features for portable and handheld medical enclosures:

Ergonomic Design	Comfortable for clinicians and patients.
Size & Weight	Compact and lightweight for ease of mobility.
Sealing	Use of gaskets or ultrasonic welding for liquid ingress protection (IP-rated enclosures).
Cable Management	Routing for power or data cables in compact spaces.

Find out how our medical device contract manufacturing services can simplify your complex enclosure projects.

Design Tips

When designing small medical device enclosures and housings, consider the following tips:

• Incorporate snap-fit features to simplify the assembly process.
• Plan the enclosure layout to accommodate displays and control buttons effectively.
• Add surface textures or coatings to improve grip and support antimicrobial performance.

These elements are essential parts of enclosure design, helping to ensure optimal usability and compliance in medical settings.

Regulatory and Safety Compliance

Designers are responsible for ensuring that all medical enclosures comply with relevant regulatory and safety standards.

IEC 60601-1	Electrical safety for medical devices.
ISO 13485	Quality management system requirements.
FDA Guidelines	Materials must be listed or cleared for medical use.
Ingress Protection (IP Ratings)	Defines protection from solids and liquids.

Other Considerations

Other key standards and certifications to keep in mind when designing small medical device enclosures include:

• Flammability requirements, such as UL 94 V0
• Risk management standards, such as ISO 14971
• EMC shielding requirements

Manufacturing Considerations

Design engineers should work closely with manufacturers early on to optimize enclosure designs based on the following manufacturing considerations:

Tooling Feasibility	Designs should be moldable with proper draft angles.
Tolerance Stacking	Important for snap fits and closures in small parts.
Surface Finish & Aesthetics	Critical for consumer-facing medical devices.
Volume & Cost Efficiency	Match materials, tooling, and process to the expected production volume.

Explore our medical plastic injection molding services page to learn how D&M supports efficient part design and production for medical applications.

Secondary Operations

To complement our plastic injection molding capabilities, we offer a range of secondary services, including:

• Overmolding for soft grips or seals
• Insert molding for electronic components
• Pad printing or laser marking for labels and logos

Partner with D&M Plastics

Designing small housings and enclosures for portable medical devices requires careful attention to material selection, functional design, compliance, and manufacturability. From biocompatible thermoplastics to features like snap fits and ingress protection, every detail impacts safety, usability, and performance. D&M Plastics brings proven expertise in medical machine enclosure design, providing specialized support in precision medical injection molding, tooling, material selection, and secondary operations like overmolding and pad printing.

Connect with D&M Plastics to streamline your development process and deliver high-performance, FDA-compliant enclosures for your medical devices.

Contact our team or request a quote today to discuss your next project.

Frequently Asked Questions

What makes a plastic housing suitable for medical use?

Plastic housings for medical devices must be made from biocompatible materials that can tolerate sterilization, chemical exposure, and high temperatures. These materials should comply with FDA or ISO requirements.

How do I ensure my enclosure is compliant with FDA regulations?

Choose FDA-grade materials and design with risk management and safety in mind. Medical devices are classified by the FDA into three classes based on risk, with compliance requirements increasing with each class:

• Class 1: Low risk, facing fewer regulatory requirements
• Class 2: Moderate risk, requiring more regulatory controls
• Class 3: Highest risk, typically for implantable or life-sustaining devices

It’s also important to partner with a certified manufacturer familiar with ISO 13485 and FDA requirements.

What types of plastics are best for medical devices to be sterilized?

Plastics such as PEEK, polysulfone, and certain grades of polypropylene and polycarbonate are suitable for sterilization methods like autoclaving and gamma radiation.

How early should I involve a molder in the design process?

Start collaborating with your contract manufacturing partner as early as possible. This guarantees manufacturability, accelerates DFM reviews, and helps prevent expensive redesigns.