We all need medical care—from the day we are born, until the day we die. This need is ever present and has not changed in hundreds of years, but it has been dramatically accentuated in recent years by a global convergence of chronic diseases (such as obesity, arteriosclerosis, diabetes, and cancer, among others); Increased world population (now estimated to be in excess of 7.3 billion and growing at ~1.1% annual rate) has also contributed towards this need of medical care. All of these factors have created a pervasive reliance on advanced biomedical instrumentation and sensors as tools for patient diagnosis, monitoring, treatment and care, as well as the adoption of minimally invasive surgery (MIS) coupled with the advent of medical robotics and computer-assisted surgical systems (MRCAS).

Optical fiber and fiber-based sensors (FOS) are ideally suited for a broad variety of—invasive and non-invasive—applications in life sciences, clinical research, medical monitoring and diagnostics, ranging from simply lighting guides for illumination purposes, to fiberscopes for internal organ observation, and high-power resistant assemblies for laser delivery applications. Optical fibers have also made tremendous inroads in more advanced applications, such as in optical coherence tomography (OCT) probes, for non-invasive external tissue and organ imaging, force-sensing catheters in robotic surgery, to intra-aortic pressure probes. A broad variety of FOS have been developed and commercialized over the past 30 years to measure a broad variety of different physiological parameters such as body temperature, blood pressure, respiration, heart rate, blood flow, muscle displacement, cerebral activity, and many others; In addition to bio-chemical sensors for monitoring of metabolic variables and compounds such as pH, blood oxygen, glucose, etc.

Aspect of a miniature fibre optic Fabry-Perot biomedical pressure sensor
(Reproduced with permission of FISO Technologies)

The healthcare industry is demanding the development of smaller disposable sensing catheters for use in MIS and MRCAS applications, as well as for diverse patient sensing probes, for which optical fibers are ideally suited given their small size, lightweight and compatibility with sterilization techniques. However, biomedical sensors and devices present some unique design challenges.   Sensors need to be safe, reliable, highly stable, biocompatible, amenable to sterilization and autoclaving, not prone to biologic rejection, and not require calibration or at least maintain it for prolonged times.

For sure optical fibers—and devices and sensors based on their use—make for a powerful and versatile, enabling technology lighting the way to new research and commercial development of present and future bio-medical sensors, instruments and techniques for diagnostic, therapy and surgical applications in the healthcare industry.

Author: Alexis Mendez

MCH Engineering, LLC