How researchers are returning sensation to breast cancer survivors

Using some of the concepts developed for the bionic hand, the researchers plan to embed a flexible sensor array under the skin of mastectomy patients. Activated any time the nipple-areolar complex is touched, the sensor array sends signals to a series of electrodes that stimulate the patient’s residual intercostal nerves—nerves that used to interface with the breast.

“You can create vivid sensations of touch by electrically activating the nerves of the hand,” explained Bensmaia, noting that the Bionic Breast will foster re-embodiment of the patient’s chest. “It can feel like a part of their body again,” he said.

The work is backed by the National Cancer Institute R21 grant mechanism, which is intended to encourage exploratory research and gives the researchers two years to establish a working relationship and do the foundational and development work needed to warrant a longer-term, larger-scale investment.

As part of this, the researchers also are collating a list of subjective and objective criteria by which to measure breast function. “If we want to study the relationship between breast cancer treatment and breast function, we need a measure to assess breast function—and that did not exist,” said Lindau, whose lab is leading this work with input from a patient advisory board that has been helping define the right questions to ask and the right people with which to collaborate.

While Lindau’s team is well on its way to developing a measure that can also be used by others, Bensmaia is in parallel conducting the physical testing to quantify breast sensation. His team has developed a rig that enables the researchers to precisely quantify sensory perception in the breast—an adaptation of one used in their work studying hand sensation.

Testing the sensor technology subcutaneously for an extended period of time is the last technology development piece left to complete. Sihong Wang, an assistant professor at the UChicago Pritzker School of Molecular Engineering, is developing the tissue-like pressure sensors that can be structurally and functionally integrated into the Bionic Breast.

“Such sensors can work similarly as the sensing receptors in the breast for sensing physical contact/movement, by converting it to an electrical signal,” Wang said. “Our major steps are to build such sensors with tissue-like soft materials that are biocompatible for implantation, and to use the electrical signal to communicate with the artificial peripheral neural devices that Sliman will build.”

Mastectomy and reconstruction often happen in multiple stages, during which the researchers can implement the sensor array, giving them the opportunity to prototype without subjecting patients to additional surgeries. “It’s much less invasive than bionic hands, which require a special surgery to make that work,” Bensmaia said.

The researchers also plan to apply for an additional grant, which will help lay the foundation for studies in animal models and humans.

“This has the clearest path forward in just about anything I’ve ever done. All the components are in place,” Bensmaia said. “I am very confident this is going to work and help millions of women around the world.”

The researchers worked with the Polsky Center to file a patent application for the technology.

Citation: “Using Bionics to Restore Sensation to Reconstructed Breasts.” Lindau and Bensmaia, Frontiers in Neurorobotics, May 8, 2020.

Funding:  National Cancer Institute, Janet D. Rowley Discovery Fund at the University of Chicago Comprehensive Cancer Center.

—Adapted from an article originally posted by the Polsky Center.