Researchers at the University of California, Los Angeles (UCLA) have created a 3D printed pen that detects subtle tremors in handwriting, offering a potential tool for diagnosing Parkinson’s disease.
Co-authored by Professor Jun Chen, the device relies on magnetic particles and electrical signals to record small movements linked to the neurodegenerative disorder. The professor explained that the pen quantifies tremors during writing by measuring the electrical signals generated as handwriting occurs.
Published in Nature Chemical Engineering, the team’s findings suggest that this low-cost pen system could be a practical diagnostic option, especially in areas with limited access to advanced medical testing. Chen told The Guardian that the system is “very cost-effective and fully accessible for lower income countries,” and he envisions it eventually linking to smartphone apps to simplify analysis.
Rethinking diagnosis for a global disease
Impacting over 10 million people globally, Parkinson’s causes symptoms like tremors, muscle stiffness, and slowed movements that often appear slowly. Early detection is key for better treatment and support, but diagnosis typically relies on subjective assessments or costly biomarker tests that require advanced equipment and trained professionals, said the UCLA team.
To address these challenges, the UCLA team designed a pen that features a soft silicone tip embedded with magnetic particles, paired with an ink containing fine particles that react to the tip’s magnetic field during movement. As a person writes or draws, the magnetic properties of the tip change, generating a voltage in a coil inside the pen.
These voltage shifts produce electrical signals that track the hand’s movements while writing. For the study, participants drew shapes like wavy lines and spirals or wrote letters, both on surfaces and in the air, while the pen recorded precise motion patterns.
Then, the research team used machine learning models to analyze the recorded signals and identify patterns that could point to Parkinson’s disease. In a small pilot study with 16 participants of which 3 included Parkinson’s, one of the models reached an average accuracy of over 96.22% in identifying healthy participants from those with the disease.
While these initial results appear promising, some experts believe more data is needed to confirm the pen’s potential as a diagnostic tool.
Oxford University’s associate professor of clinical neuroscience, Dr. Chrystalina Antoniades, noted that although handwriting changes can signal Parkinson’s, other symptoms must also be considered. She said the pen could serve as an extra diagnostic tool rather than a complete solution.
Additionally, Becky Jones, Research Communications Manager at Parkinson’s UK, said the pen’s approach was encouraging but noted the study’s small scale. She pointed out that there is still no single test for Parkinson’s and that handwriting changes can be an early clue. Jones called for larger and more diverse studies to better understand how this method could help with earlier and more precise diagnoses.
3D printing research in Parkinson treatment
Beyond UCLA’s work, 3D printing has been explored in other Parkinson’s disease research in studies investigating how it can enhance treatment and drug delivery.
In 2020, UK-based engineering company Renishaw completed a Phase 1-2 clinical trial with pharmaceuticals expert Herantis Pharma to investigate a new drug delivery device for Parkinson’s disease.
Using 3D printed titanium ports and implanted catheters, the device was designed to deliver cerebral dopamine neurotrophic factor (CDNF) directly into the brain. At the time, seventeen patients took part, receiving either placebos or monthly doses of CDNF for six months. Initial results showed the device worked safely and accurately, offering a promising way to deliver treatment.
Few years before this, University of Nottingham scientists and GlaxoSmithKline (GSK) showed that combining inkjet 3D printing with UV curing could produce solid oral dosage forms of drugs.
In their study, they created batches of 25 tablets containing Ropinirole HCl, a treatment for restless legs syndrome (RLS) and Parkinson’s disease, using a modified Dimatix Materials Printer DMP-2850. This approach offered precise, low-cost production of tablets with controlled release profiles. The team suggested it could open the door to personalized medicine and small-scale clinical trials, as well as easier adjustments to tablet shape and drug delivery characteristics.
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Featured image shows design and working mechanism of the magnetoelastic diagnostic pen. Image via UCLA.
