Despite advancements in various imaging modalities, the simple sense of touch has remained among the most-effective means of detecting breast and prostate cancer. But while breast exams and digital rectal exams have proven to be reliable methods of detection, they are subjective in nature. By capturing and quantifying the sense of touch into reproducible, objective data, however, capacitive tactile sensor solutions hold the potential to revolutionize cancer detection.
Just as the blind have long learned to paint an image in their minds by tracing their hands over a person or object, so, too, can tactile sensors yield images through contact mechanics. To effectively create innovative products that exploit capacitive tactile sensor technology, however
When Pressure Profile Systems (PPS) began targeting medical device applications for our capacitive tactile sensing technology, I didn’t realize just how many lives we might touch.
Minimally invasive surgery (MIS) has revolutionized patient care by dramatically reducing trauma and recovery time. Yet despite the benefit for patients, this transition to minor incisions has presented a major obstacle for some surgeons who lament the loss of their sense of touch during a procedure. In an effort to meet this unmet clinical need, researchers are exploring ways to replicate the sense of touch through the integration of capacitive tactile sensors into next-generation MIS instruments.
The incorporation of capacitive tactile sensing technology into medical, robotics, automotive, and a host of other applications is paving the way for the development of many innovative products. But there are inevitably still a few bumps in the road to producing a commercializable product that features sophisticated tactile pressure sensors.
Achieving proper implant placement and alignment during knee-replacement surgery is a feat that literally requires a delicate balancing act by orthopaedic surgeons. By spurring the development of emerging knee-balancing technologies, however, capacitive tactile sensors hold the potential to improve postoperative function and pain relief by supplying quantifiable pressure data.
For patients suffering from esophageal disorders and searching for answers, the lack of information gleaned from procedures such as manometry used to be tough to swallow. Advancements in high-resolution tactile pressure sensing technology, however, have led to the development of the ManoScan 360 motility visualization system, which provides clinicians with greater detail, accuracy, and data to aid in diagnosis of esophageal problems.
Entailing the insertion of a sensor-equipped catheter through the nose and down through the esophagus and into the stomach, esophageal manometry is performed to assess function of the organ as it moves food down into the stomach through a process called peristalsis.
“The test measures how well the circular bands of muscle (sphincters) at the top and bottom of your esophagus open and close, as well as the pressure, strength, and pattern of the wave of esophageal muscle contractions that moves food along,” according to The Mayo Clinic.
And while esophageal manometry had, for years, enabled the diagnosis of such conditions as dysphagia, achalasia, gastric reflux, and scleroderma, for example, its usefulness had been somewhat limited. Conventional motility catheters typically featured just four to six pressure sensors, and the information they relayed was not particularly precise or easy to interpret. As a result, doctors were often reduced to simply saying whether or not the esophagus was performing normally.
Dissatisfied with this lack of data, Dr. Ray Clouse, who was a professor of medicine and psychiatry that specialized in gastroenterology at Washington University in St. Louis at the time, sought an alternative solution. Clouse believed that a motility catheter that yielded additional feedback on pressures occurring in the organ might lead to better diagnoses of esophageal disorders.
With this goal in mind, he developed a catheter system outfitted with a higher number of sensors. However, this system ultimately proved to be too cumbersome and, as it relied on a series of water pumps, difficult to maintain.
With the help of a motility catheter salesperson, Pressure Profile Systems (PPS) became involved with the project, driven by the realization that the application of tactile pressure sensor arrays could result in a workable solution. After two years—and with the assistance of a grant from the National Institutes of Health—PPS developed a custom motility catheter that incorporated 36 multiplexed circumferential pressure sensors.
Dubbed the ManoScan 360, the 36-element catheter system collects information about esophageal performance in much greater detail than was previously possible, and presents that information in a visual, easy-to-understand manner. In fact, the system provides a spatial resolution of nearly 10 times that of its predecessors.
Thanks to the incorporation of the numerous tactile pressure sensors, the system captures all relevant motor function measurements from the pharynx down to the stomach. Whereas physicians previously had to puzzle out a diagnosis from limited manometry readings, they now have an easy-to-understand view of how the esophagus is functioning from the inside. Isolating and diagnosing problems has become as simple as looking at a pressure map generated by the measurements taken from the complex capacitive tactile sensor arrays.
The driving concept of optimizing the product for the end-user is further exemplified in the product’s flexibility based on user preference. Rather than forcing this newer approach on healthcare providers, the manometry system was designed to accommodate those who were used to the status quo and might be resistant to change. To that end, the product’s software also includes the option to display pressure data in the conventional format that clinicians had been using for years.
The ManoScan 360 was ultimately introduced to the market in 2004 by a spinout company called Sierra Scientific Instruments (SSI). SSI was acquired by Given Imaging in 2010, which now markets the product as the ManoScan ESO.
Checking one’s pulse is both simple and familiar: Press two fingers against the radial artery in the wrist and count the beats to determine heart rate. But while this act can indicate heart rhythm and strength of pulse, it reveals little else about a person’s health. Thanks to capacitive tactile pressure sensing technology, however, this most basic of medical procedures can now be leveraged to obtain more-insightful patient data.
In the world of tactile pressure sensors, you’re often only as good as what you’re able to demonstrate. As such, calibrating pressure sensors is a crucially important process.
Often intimidated by the relatively new technology, many engineers tend to err on the side of caution and overspec capacitive tactile sensor solutions. They want it all: the best resolution, the most sensors, the fastest speeds, and the best performance. Unfortunately, that wish list simply isn’t feasible.