Neuralink Reports Hardware Malfunction in First Human Subject: Electrode Threads Detached, Causing Data Loss

Elon Musk’s path to “human-machine symbiosis” has not been smooth, as his brain-computer interface company, Neuralink Corp, revealed that the device implanted in its first human subject experienced hardware issues.

On May 8 local time, Neuralink stated in a blog post that within weeks after performing surgery on patient Nolan Arbo in January, some wires embedded in the brain tissue became dislodged, affecting the information transmission rate and causing partial data loss, which resulted in the device malfunctioning.

Neuralink stated that a detached wire led to a decline in bits per second, a metric measuring the speed and accuracy with which Arbo controls the computer cursor using only his thoughts.

Neuralink stated that it resolved the electrode wire issues by modifying the recording algorithms to enhance sensitivity to neural population signals and improving the technology that translates signals into cursor movement, “resulting in rapid and sustained improvements that have now surpassed the initial performance of Nolan’s (implantable device).”

According to foreign media citing informed sources, one factor under investigation by Neuralink is that air entered Arbo’s cranial cavity following the implantation surgery, a condition known as pneumocephalus. This issue does not appear to pose a threat to Arbo’s safety. Nevertheless, the sources stated that researchers are considering the possibility of removing the device implanted in Arbo’s brain.

For Neuralink, which is seeking to conduct broader clinical trials, any malfunction could lead to delays in the U.S. Food and Drug Administration (FDA) approval process.

Earlier in March, Neuralink announced updates on Nolan’s implant progress, stating that the quadriplegic man had already been able to play video games and online chess using his thoughts. At the time, Musk also stated that Nolan was recovering well, “appearing to have fully recovered with no known adverse effects.”

Brain-computer interface (BCI) core technology is a novel communication and control method that establishes a connection between the human or animal brain and computers or other electronic devices, independent of conventional brain information output pathways (peripheral nerves and muscle tissues). Based on the technical communication pathways, BCI technologies are primarily categorized into three types: “non-invasive (extracranial),” “invasive,” and “semi-invasive.”

Neuralink employs an invasive approach, directly implanting electrodes into the cerebral cortex via surgical procedures to acquire high-quality neural signals. The company’s current N1 implant records neural activity using 1,024 electrodes distributed across 64 threads, with highly flexible, ultra-fine electrode wires being key to minimizing damage during and after implantation.

Neuralink stated that it is currently working on improving text input and cursor control for its brain-computer interface devices, with the ultimate goal of expanding into the physical world to enable control over robotic arms, wheelchairs, and other technologies, thereby enhancing independence for patients with quadriplegia.

Elon Musk has previously claimed on multiple occasions that implantable brain-computer interface devices could enable paralyzed individuals to walk again, restore vision to the blind, and achieve “human-machine symbiosis,” among other possibilities.

Neuralink, founded in 2016, primarily focuses on brain-computer interfaces (BCIs), aiming to achieve “human-brain–machine interaction” by developing implantable devices. Since its inception, the company has secured multiple rounds of funding. According to foreign media reports, Neuralink’s valuation had already exceeded $5 billion by June 2023. In a private financing round of $205 million two years prior, its valuation was close to $2 billion.

Responsible Editor: Wei Zirong