Canadian engineering students’ thermal melanoma detector wins international design prize.
Melanoma, an easily preventable but aggressive form of skin cancer, is not only one of the most common and deadly but also trickiest cancers to detect. The problem is that melanoma can hide in plain sight, masked by moles and other benign blemishes, and thereby evades initial detection, which relies on a doctor “eyeballing” suspicious legions.
As a consequence, it is, paradoxically, both easy to miss during a routine examination yet often needlessly tested for by biopsy, in the name of being better safe and sorry. In fact, the majority of biopsies return a negative result, yet an estimated 1,250 Canadians still die from melanoma annually or 3.4 deaths per day. In sunnier climates, like the U.S., those numbers climb to 9,730 deaths annually or one person per hour.
Given this, four McMaster University electrical and biomedical engineering grads (including Shivad Bhavsar, Rotimi Fadiya, Prateek Mathur and Michael Takla) hope to remove the uncertainty from skin cancer screening. As their senior project, they designed and built the sKan, an inexpensive handheld device designed to spot melanoma in its earliest and most treatable stages. According to the team’s mentor, Dr. Raimond Wong, who serves as Chairman of the Gastrointestinal Oncology Site Group at the Juravinski Cancer Centre, their project has potential well beyond the classroom.
“Current methods of detecting whether a lesion is melanoma or not is through the trained eyes of physicians – resulting in patients undergoing unnecessary surgery or late detection of melanoma,” said Dr. Wong. “The sKan has the potential to be a low cost, easy-to-use and effective device, which can be afforded and adopted across health services.”
He isn’t the only one with high regard for the sKan. In November, the James Dyson Foundation named the McMaster University team as the winner of the international James Dyson Award, an annual competition that recognizes the next generation of design engineers and their inventions. To win the international competition’s $50,000 prize, the sKan team beat out national Dyson Award winning projects from 23 countries.
What set the sKan project above the rest, James Dyson said, was their clever use of inexpensive components to create a potentially life saving device. The sKan takes advantage of the fact that cancer cells release more heat than healthy cells. Cancerous tissue regains heat faster, after a patch of skin has been cooled, which can indicate a strong likelihood of melanoma.
“In its early stages, melanoma is harmless and its removal is easy but, if left undetected, it can become quickly lethal,” says Michael Takla. “Knowing that, we came across research in our fourth year showing that it could be detected by looking at thermal recovery… so we asked why that technique hadn’t be used previously.”
“We found that this approach had only been employed with high-end infrared cameras that cost between $10,000 to $200,000, which is too expensive for a family physician to incorporate into their clinic,” he adds. “So that’s what we tackled: Create a device that uses the same thermal principle but make it affordable.”
To detect that rise in temperature, the sKan uses a small transducer with an array of 16 thermistors laid out in a grid pattern. Pressing the hand-held device to cooled skin allows the sensors to detect which cells return to normal temperature fastest. A conditioning circuit filters and amplifies the sensors data before a microcontroller unit digitizes it.
The conditioned signal is then sent to a computer that formats and fits the signal to the thermistors’ parametric curves and displays the results as a heat map and temperature difference over time. Provided this data, doctors and other medical personnel would be able to quickly assess the presence, or absence, of melanoma. All told, Takla says the component cost for the sKan totalled approximately $1,000 for the prototype device.
“Our next step will be to enter a more intense prototyping phase,” Takla says. “That will includes improving the quality and resolution of the thermistors, reducing the electrical noise as much as possible and improving our detection algorithm. After that, the goal is to enter pre-clinical testing over the coming months to a year.”