3D Printing Silicone Elastomer for Patient-Specific Wearable Pulse Oximeter

Area of Science:

• Biomedical Engineering
• Materials Science
• Wearable Technology

Background:

• Commercial pulse oximeters, essential for monitoring heart rate and blood oxygen saturation, are typically rigid and uncomfortable for continuous use.
• Existing soft oximeters offer better comfort but require time-consuming molding for patient-specific fits.
• A need exists for rapidly customizable, comfortable, and accurate wearable oximetry devices.

Purpose of the Study:

• To develop a novel method for fabricating patient-specific, soft pulse oximeter cuffs using 3D printing.
• To demonstrate the feasibility of creating wearable devices with integrated pressure sensing capabilities.
• To evaluate the accuracy and performance of these custom devices compared to commercial oximeters.

Main Methods:

• Utilized freeform reversible embedding (FRE) 3D printing to fabricate polydimethylsiloxane (PDMS) elastomer cuffs.
• Employed a sacrificial hydrogel bath to support liquid PDMS during 3D printing and curing.
• Conducted a sizing analysis to validate dimensional accuracy against CAD models and integrated pressure sensors.

Main Results:

• Successfully fabricated patient-specific PDMS cuffs with accurate dimensions using FRE printing.
• The P3-wearable device wirelessly transmitted photoplethysmography (PPG) and pressure signals in real time.
• Calculated heart rate, blood oxygen saturation, and activity state from PPG signals with accuracy comparable to commercial devices.

Conclusions:

• FRE 3D printing enables rapid, customized fabrication of soft, wearable medical devices.
• Patient-specific PDMS oximeter cuffs offer a viable alternative to rigid devices for continuous monitoring.
• The P3-wearable demonstrates potential for improved patient comfort and adherence in wearable health technology.