IEEE SENSORS JOURNAL, VOL. 3, NO. 3, JUNE 2003 251 Emerging Biomedical Sensing Technologies and Their Applications Gerard L. Coté, Senior Member, IEEE, Ryszard M. Lec, Member, IEEE, and Michael V. Pishko Abstract—Recent progress in biomedical sensing technologies has resulted in the development of several novel sensor products and new applications. Modern biomedical sensors developed with advanced microfabrication and signal processing techniques are becoming inexpensive, accurate, and reliable. A broad range of sensing mechanisms has significantly increased the number of possible target measurands that can be detected. The miniatur- ization of classical “bulky” measurement techniques has led to the realization of complex analytical systems, including such sensors as the BioChemLab-on-a-Chip. This rapid progress in minia- ture devices and instrumentation development will significantly impact the practice of medical care as well as future advances in the biomedical industry. Currently, electrochemical, optical, and acoustic wave sensing technologies have emerged as some of the most promising biomedical sensor technologies. In this paper, important features of these technologies, along with new developments and some of the applications, are presented. I. INTRODUCTION T HE ongoing mergence of the 20th century revolution in information technology with the 21st century revolution in biotechnology poses considerable demand for new sensors, in particular new biomedical sensors. Currently, the recent advances in the microelectronics industry, the availability of advanced microfabrication technologies down to the micro- and nanoscale, and inexpensive signal processing systems have made the development of a variety of novel biomedical sensors possible. A good indication of that demand is the growing use of per- sonal monitoring devices such as glucose sensors for diabetics or the recently developed sensors for HIV detection. Biomed- ical sensors can also make medical care more personal and tai- lored to the individual needs of a patient. In the near future, a treatment procedure could be adjusted to address a patient’s unique metabolism and biological rhythms. For example, the dose of a drug could be correctly determined in order to opti- mize the healing process and minimize its side effects. In addi- tion, biomedical sensors will enable a broad range of medical Manuscript received May 23, 2001; revised June 10, 2002. The associate ed- itor coordinating the review of this paper and approving it for publication was Prof. Henry Baltes. G. L. Coté is with the Department of Biomedical Engineering Program, Texas A&M University, College Station, TX 77843-3120 USA (e-mail: cote@tamu.edu). R. M. Lec is with the The School of Biomedical Engineering, Science and Health Systems, and the Department of Electrical and Computer Engineering, Drexel University, Philadelphia, PA 19104 USA (e-mail: rlec@cbis.ece.drexel.edu). M. V. Pishko is with the Department of Chemical Engineering, Penn- sylvania State University, University Park, PA 16802 USA (e-mail: mpishko@engr.psu.edu). Digital Object Identifier 10.1109/JSEN.2003.814656 services at a patient’s home using a variety of systems that em- ploy a personal computer and the Internet. One may envision a dedicated home-based analytical diagnostic system interfaced with a computer that could monitor and store medical data over the life time of the person. In such a case, specialized application software would be capable of recognizing incoming health prob- lems and could notify a person in advance of her or his health conditions. A modern biomedical sensor is a device which consists of a biologically or biophysically-derived sensing element inte- grated with a physical transducer that transforms a measurand into an output signal. The requirements for any good biomedical sensor are specificity or the ability to pick out one parameter without interference of the other parameters, sensitivity or the capability to measure small changes in a given measurand, accuracy or closeness to the true measurement, time response, biocompatibility, aging characteristics, size, ruggedness and robustness, and low cost. In addition, the sensor must have compatibility with the chemical, optical, optoelectronic, or electronic integrated circuit (IC) technology. The above listed features have been researched comprehensively over the last two decades and critical knowledge has been accumulated and the challenges have been identified. One may claim that the biomedical sensor field has matured enough to be poised for commercial success. In this paper, an overview of three of the primary biomedical sensor technologies; electro-chemical, optical and acoustic are discussed along with many of the biomedical applications. II. MODERN BIOMEDICAL SENSORS A conceptual model of a biomedical sensor and its impor- tant design elements are shown in Fig. 1. This model presents a complete biomedical sensor scheme in which, in addition to a sensing section of a biomedical sensor, microfluidic, signal pro- cessing and packaging units are included. Simultaneous analysis and design of all these elements are essential for the develop- ment of marketable biomedical sensors. The principle of operation of such a biomedical sensor can be inferred by following its sensing path. A measurand is in- troduced to a biomedical sensor using sample delivery system or by bringing the sensor to the patient, as with implantable or indwelling biomedical sensor probes. Next, the measurand passes through a preprocessing section, such as semi-permeable membrane, which performs a initial selective screening of pos- sible interfering factors. After that, the measurand is exposed to the sensing element, a biologically active substance which is selective to the measurand of interest (i.e., DNA, antibodies, 1530-437X/03$17.00 © 2003 IEEE