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Maidstone, United Kingdom

Rolfe P.,Oxford BioHorizons Ltd. | Rolfe P.,Harbin Institute of Technology | Rolfe P.,Waseda University
Key Engineering Materials

This paper reviews the ways in which micro and nano sensors have evolved within biology and medicine. The target measurands include an ever-increasing number of simple and complex molecules, physical quantities, and electrical and magnetic phenomena. Micro sensors based on electrochemical, acoustic, piezoelectric and optical principles are contributing to clinical care of patients who may benefit from the continuous monitoring of critical variables in intensive care or from the ability to perform convenient self-monitoring during normal daily life. Sensors constructed on the nano-scale are now emerging, especially for complex bio-molecules such as DNA. These are strengthening basic research, for example in the study of genetic factors in disease and for discovery of new drugs. Scanning probe technology and nano optics, including surface enhanced Raman spectroscopy, play important roles in these developments. Sensor science and technology has gained significant benefits through inspiration arising from biological sensory systems. This includes the sense of olfaction, which has led to the artificial nose, and the sense of vision that has been emulated in several versions of the artificial retina. The impact of micro and nano sensors on fundamental understanding in biomedicine and on clinical diagnosis and care are highlighted. © (2010) Trans Tech Publications. Source

Yamakoshi T.,Kanazawa University | Matsumura K.,Kanazawa University | Rolfe P.,Harbin Institute of Technology | Rolfe P.,Oxford BioHorizons Ltd. | And 3 more authors.
Aviation Space and Environmental Medicine

Introduction: We report a new methodology for detecting heat illness based on continuous tympanic temperature monitoring. This is relevant to industrial workers, astronauts, and pilots, as well as athletes. Here we evaluate the method in Grand Touring (GT) car racers in the closedcockpit category who can face life-threatening hyperthermia. Methods: The system comprises an earpiece containing an infrared-radiation-type tympanic thermometer and a microspeaker. In 10 healthy subjects, using a temperature-controlled water bath in the laboratory, we determined the differences in measurements taken from an infrared thermometer in one ear canal and from a thermistor probe in the other ear canal for direct tympanic temperature measurement. We employed an ingestible telemetry pill for gastrointestinal temperature measurement as a reference of core temperature. Then we assessed the usefulness of the system under real racing conditions with two professional drivers in the 2010 Super GT International Series held at the Twin Ring Motegi in Japan. Results: The results showed a good correlation between the infrared tympanic temperature and both the direct one ( r = 0.985) and the gastrointestinal temperature ( r = 0.932). The mean difference between these temperatures was 1 0.01°C and 1 0.27°C, with 95% confidence intervals (equal to 1.96 SD) of 0.30°C and 0.58°C, respectively. As for the field test, the system functioned well during real competitive and extremely severe race conditions on the racing circuit. Conclusions: The new method was found to perform well in an extreme car racing setting. It has the potential to be used in other applications, including the industrial and aerospace sectors. © by the Aerospace Medical Association, Alexandria, VA. Source

Yamakoshi T.,Kanazawa University | Matsumura K.,Kanazawa University | Rolfe P.,Harbin Institute of Technology | Rolfe P.,Oxford BioHorizons Ltd.
Transportation Research Part C: Emerging Technologies

Vehicle-related countermeasures to sustain driver's alertness might improve traffic safety. The purpose of this study was to investigate the effects of somatosensory 20. Hz mechanical vibration, applied to driver's right heel during prolonged, simulated, monotonous driving, on their cardiovascular hemodynamic behavior. In 12 healthy young male volunteers, during 90-min periods of simulated monotonous driving, we compared cardiovascular variables during application of 20. Hz mechanical vibration with 1.5. Hz as a control and with no vibration. The parameters recorded were indices of key cardiovascular hemodynamic phenomena, i.e., blood pressure as an indicator of stress, cardiac output, and total peripheral-vascular resistance. The principle results were that all conditions increased the mean blood pressure, and elicited a vascular-dominant reaction pattern typically observed in monotonous driving tasks. However, mean blood pressure and total peripheral-vascular resistance during the monotonous task were significantly decreased in those receiving the 20. Hz vibration as compared with 1.5. Hz and with no vibration. The observed differences indicate the cardiovascular system being more relieved from monotonous driving stress with the 20. Hz vibration. The major conclusion is that applying 20. Hz mechanical vibration to the right heel during long-distance driving in non-sleepy drivers could facilitate more physiologically appropriate status for vehicle operation and could be a potential vehicular countermeasure technology. © 2013 Elsevier Ltd. Source

Yamakoshi T.,Kanazawa University | Matsumura K.,Kanazawa University | Rolfe P.,Oxford BioHorizons Ltd. | Hanaki S.,Kanazawa University | And 5 more authors.
IEEE Journal of Biomedical and Health Informatics

We explored the potential of health screening based on the long-term measurement of cardiovascular parameters using the finger volume-oscillometric technique. An automated instrument made simultaneous measurements of key cardiovascular parameters, including blood pressure, pulse pressure, heart rate, normalized pulse volume as an index of α-adrenalin-mediated sympathetic activity, and finger arterial elasticity. These were derived from finger photo-plethysmographic signals during application of cuff pressure. To assess the feasibility of achieving a screening function, measurements were made in ten healthy volunteers during 10 days of day-to-day living (normal condition), and carried out several times at a fixed time every day. During successive 10-day measurements, a 30-hour period of total sleep deprivation was introduced as a physiological challenge (abnormal condition). A linear discriminant analysis of the data was conducted to determine whether these two conditions could be discriminated. Periodic data collection was performed rapidly and easily, and the %-correct classifications of normal and abnormal conditions were 78.2% and 77.5%, respectively. This ability of the method to discriminate between regular and sleep-deprived activities demonstrates its potential for healthcare screening during day-to-day living. Further investigations using larger age and gender groups of subjects including patients with cardiovascular diseases under real-life situations are required. © 2013 IEEE. Source

Rolfe P.,Oxford BioHorizons Ltd. | Rolfe P.,Harbin Institute of Technology
Sensors and Materials

Micro- and nanosensors have evolved rapidly in the last few decades and they have expanding roles within biology and medicine, where measurement science and technology is of key importance. The targets for measurement include a huge number of simple and complex molecules, physical quantities such as pressure, force, displacement and flow, and electrical and magnetic phenomena arising from the heart, brain, muscles and nerves. Routine clinical care of patients currently benefits from the use of macro- and microscale sensors based on electrical, electrochemical, acoustic, piezoelectric and optical principles. Disposable electrodes for recording biopotentials, such as the electrocardiogram and electroencephalogram, are common, whereas invasive electrochemical and optical fibre sensors for pressure, blood gases and pH are useful in intensive care. Microscale immobilised enzyme glucose sensors are largely confined to the analysis of small blood samples, their invasive use still facing technical challenges. Sensors constructed to the nanoscale using quantum dots and carbon nanotubes are now rapidly emerging, being aimed at more complex biomolecules such as DNA. Nanoparticles in general and surface-enhanced Raman spectroscopy also play important roles in these developments. The impact of micro- and nanosensors on the fundamental understanding of major biomedical challenges and on clinical diagnosis and care are highlighted here. Source

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