Physiological measurement in biomedical research
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2004-08-01
The key to managing a process or system is accurate measurement. From an engineering viewpoint, accurate measurement and acquisition of system observers is a fundamental necessity in order to model, understand and ultimately control a system. From a clinical viewpoint, the basis of a diagnosis is derived from observations and measurements. In this special issue of Physiological ...
Medical electronics and physiological measurement
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 1989-07-01
This article describes some recent developments in physiological measurement since the last `special issue' in 1978. Nine examples are given covering mature applications, new techniques and some `ideas for the future'. The need for good scientists in this interesting and challenging area is stressed. Physiological measurement is challenging because human ...
Measurement of physiological parameters in tumors in vivo using MPLSM
Proc. of SPIE;PSI Volume 4262 Issue 1 2001-04-24
Conventional epifluorescence microscopy coupled with chronic animal window models has provided stunning insight into tumor pathophysiology, including gene expression, angiogenesis, interstitial transport, and drug delivery. However, the findings to date have been limited to the tumor surface ([less-than] 150 microns). This is an important drawback because the internal architecture of tumors is known to be heterogeneous, with a collagenous tumor/host interface, highly vascularized outer regions, and ...
Measurement of physiological flow parameters with magnetic resonance
Proc. SPIE Int. Soc. Opt. Eng.;PSI Volume 1887 Issue 1 1993-08-27
Some phase-sensitive methods obtain a phase measurement for each voxel in an otherwise conventional image. In an alternative approach, data for a variety of flow-sensitive conditions are obtained and Fourier transformed to obtain a velocity 'spectrum'. Fourier velocity encoded data are highly accurate and are not degraded by velocity distributions within a voxel. One important application of Fourier velocity encoding is the non-invasive measurement ...
Photoplethysmography and its application in clinical physiological measurement
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2007-03-01
Photoplethysmography (PPG) is a simple and low-cost optical technique that can be used to detect blood volume changes in the microvascular bed of tissue. It is often used non-invasively to make measurements at the skin surface. The PPG waveform comprises a pulsatile (‘’‘’
Linear and non-linear time series analysis in non-invasive physiological measurement
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 1996-01-01
Non-invasive physiological measurement covers conventional methods of indirect and derived measurement. The definition should also include minimally invasive methods which are becoming increasingly important as meter technology allows patients to collect their own data for clinical use. Across the range, non-invasive methods add noise to the interpretation process. The rise of home data ...
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2004-10-01
Ventilatory and cardiac responses to changing inhaled gas fractions are notoriously variable within individuals. Such variation can confound clinical diagnoses and hypotheses about human adaptation. In this study we use a cardiac (HHR) and a ventilatory (HVR) measure of physiological sensitivity to an experimentally manipulated oxygen concentration (8% O2), to compare variation (a) within and between individuals, (b) within ...
Microcomputer applications: physiological measurements
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 1983-01-01
Smart Spaces with Real-Time Physiological Measurement and Mitigation of Stress
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2008-01-01
We propose the use of context-aware smart space technology that is able to monitor physiological signs of a user in real-time. The smart space informs the user when they are stressed and automatically initiate an appropriate stress-relieving response via a selection of scenarios. Using the Nexus-10 we measured on single male subject physiological responses by comparison with baseline music, ...
Optical pH sensor for physiological pH measurement
Proc. SPIE Int. Soc. Opt. Eng.;PSI Volume 2085 Issue 1 1994-02-15
A miniature optical sensor based on the fluorescent indicator, 8-hydroxyl-1,3,6-pyrene trisulfonic Acid Trisodium Salt (HOPSA), was developed for physiological pH measurement. Dowex-1 strongly basic anion exchange resin was used as a medium to immobilize the indicator on the end of an optical fiber to form a pH sensing layer. Polyetherurethane was dip- coated onto the sensing layer as the permeable membrane for H[sup + ]. The ...
Piecewise-linear trend detection in longitudinal physiological measurements
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2009-01-01
Recently, telecare solutions have been demonstrated as an effective means of monitoring chronic disease at a distance. A clinician may be managing many tens or hundreds of remote patients, prompting the need for a decision support system (DSS) to provide a more automated approach to managing these vast amounts of data. While simple threshold-based alert techniques provide some utility in notifying clinicians of extreme out-of-range parameter values, more incipient changes in a subject's condition ...
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2007-01-01
Achieving and maintaining user engagement is a key goal of human-robot interaction. This paper presents a method for determining user engagement state from physiological data (including galvanic skin response and skin temperature). In the reported study, physiological data were measured while participants played a wire puzzle game moderated by either a simulated or embodied robot, both with ...
Network approach for physiological parameters measurement
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2005-01-01
A portable parameter monitoring and analysis system for physiological studies and for assisting patient-centric health care management is developed. The system uses the network approach to acquire the data from sensors and transmit them to a server through wireless propagation means. The system automates the acquisition and monitoring of physiological parameters by continuous display on the monitor screen. Programming is done ...
Physiological interpretation of electrical impedance epigastrography measurements
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2003-02-01
Measurement of the electrical impedance of the gastric region is carried out with the epigastrograph. This generates and applies alternating current around the abdominal area and measures the potential difference in order to determine the impedance externally, via electrodes. The change of epigastric impedance for a subject, given a meal after fasting, depends on the conductivity of the meal compared to the stomach and surrounding ...
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2009-01-01
Objective measurement systems and subjective evaluation techniques are used to determine thermal comfort performances of garments which is a crucial property for daily life and performance-based activities of human being. More reliable and realistic results can be obtained if the objective measurement results are combined with the physiological and psychological data obtained during subjective ...
Proc. SPIE;PSI Volume 7647 Issue 1 2010-03-25
Human state in human-machine systems highly affects the system performance, and should be monitored. Physiological cues are more suitable for monitoring the human state in human-machine system. This study was focused on developing a new sensing system, i.e. NANO-Skin, to non-intrusively measure physiological cues from human-machine contact surfaces for human state recognition. The first ...
Technologies for clinically relevant physiological measurements in developing countries
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2007-08-01
The ‘’
Proc. SPIE;PSI Volume 7291 Issue 1 2009-03-26
Potassium ion monitoring, in human body, is important for diagnostic and therapeutic purposes. The dynamic response of potassium selective ISFET sensors is instrumental in formulating calibration schema and signal compensations to correct systematic errors. In the research reported here, response characteristics of potassium selective ISFETs were studied. The range of detection was set between 1mM and 25mM to cover all the physiological potassium concentrations. ...
Design of a wireless physiological parameter measurement and monitoring system
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2007-01-01
In this paper we present the design of a wireless, low-cost system that can be used to monitor physiological parameters, such as temperature, flex angle, pulse rate and oxygen saturation in the blood, of a human subject. The system consists of an electronic device which is worn as a hand glove, by an elderly or at-risk person. Using several sensors to measure different vital signs, the person is wirelessly monitored within ...
A flexible measurement system for physiological signals in mobile health care
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2005-01-01
In the nearest future a lot of post-operative treatment and health monitoring is going to be performed in people's homes instead of in hospital. The increasing number of elderly people in the developed countries and the need for more advanced medical treatment and equipment in conjunction with economical demands will force the development of more cost-effective solutions. The equipment used must be very rugged and safe for both the patient and the operator and easily configured for a number of different ...
J. Dyn. Sys., Meas., Control;JDS Volume 97 Issue 4 1975-12-01
Abstract not available.
J. Biomed. Opt.;JBO Volume 11 Issue 6 2006-11-01
We use optical spectroscopy to characterize the influence of mammographic-like compression on the physiology of the breast. We note a reduction in total hemoglobin content, tissue oxygen saturation, and optical scattering under compression. We also note a hyperemic effect during repeated compression cycles. By modeling the time course of the tissue oxygen saturation, we are able to obtain estimates for the volumetric blood flow (1.64 [plus-minus] 0.6 mL/100 mL/min) ...
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2002-09-21
We present a model that describes the effect of physiological parameters such as the speed of blood flow, local oxygen consumption, capillary recruitment, and vascular dilation/constriction on the concentration and oxygen saturation of haemoglobin in tissue. This model can be used to guide the physiological interpretation of haemodynamic and oximetric data collected in vivo with techniques such as optical imaging, near-infrared ...
Proc. SPIE Int. Soc. Opt. Eng.;PSI Volume 6143 Issue 1 2006-03-02
Initial animal study for quantifying myocardial physiology through contrast-enhanced dynamic x-ray CT suggested that beam hardening is one of the limiting factors for accurate regional physiology measurement. In this study, a series of simulations were performed to investigate its deterioration effects and two correction algorithms were adapted to evaluate for their efficiency in improving ...
Rev. Sci. Instrum.;RSI Volume 62 Issue 3 1991-03-01
An apparatus is described, which can be used for electro-optical measurements at high ionic strengths, including physiological salt concentrations. The electric pulse is generated by the cable discharge technique; complete matching of the load impedance is achieved by a compensation cell, which is supplied with a steady flow of electrolyte solution. At a cable length of 20 m the pulse length is limited to 200 ns; the electric ...
Laser Doppler Vibrometry Measures of Physiological Function: Evaluation of Biometric Capabilities
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2010-01-01
A novel approach for remotely sensing mechanical cardiovascular activity for use as a biometric marker is proposed. Laser Doppler Vibrometry (LDV) is employed to sense vibrations on the surface of the skin above the carotid artery related to arterial wall movements associated with the central blood pressure pulse. Carotid LDV signals are recorded using noncontact methods and the resulting unobtrusiveness is a major benefit of this technique. Several recognition methods are proposed that use the temporal ...
J. Biomech. Eng.;JBY Volume 105 Issue 3 1983-08-01
Mathematical models for 1) musculoskeletal dynamics, and 2) reflex feedback, based on the results of the authors' frequeny-response measurements on normal adult male human subjects, are combined to produce a model for physiological tremor in such subjects. An analysis of this model shows that the system will be unstable to small disturbances (that is, tremor will occur) under certain conditions of external loading. Further, ...
Physics;JAP Volume 7 Issue 8 1936-08-01
The requirements of a high frequency diathermy machine for clinical therapy and for studies of physiological temperature regulation in regard to (1) frequency, (2) measurement of power output, (3) range of power output, (4) efficiency and construction are discussed. To conform with the above requirements a power oscillator of 1000 kilocycles has been built capable of delivering up to 200 watts of high frequency power. A description ...
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2006-05-31
Southeast Asian tropical rain forests are among the world's most important biomes in terms of global carbon cycling; nevertheless, the impact of environmental factors on the ecosystem CO2 flux remains poorly understood. One‐dimensional multilayer biosphere‐atmosphere models such as soil‐vegetation‐atmosphere transfer (SVAT) models are promising tools for understanding how interactions between environmental factors and leaf‐level physiological parameters ...
Volume 211, Number 2 1997-01-01
This paper describes a technique and apparatus for measuring the compressive modulus of articular cartilage under physiological loading rates. The compressive modulus is the most relevant property to the primary function of articular cartilage i.e. load carriage. It has been determined previously from measurement of cartilage deformation under slow or almost static loading conditions. The ...
Volume 215, Number 1 2001-01-01
On the issue of ultrasound measurement of cartilage thickness, in his Reply to my initial Communication [1] Dr Shepherd asserts that we 'assume' a velocity for the speed of sound in cartilage in our ultrasonic measurement of acetabula cartilage thickness and topography [2]. Page 254 of our 1981 Journal of Biomechanics article [2] states: 'Sound velocity in the respective media was experimentally determined using samples of ...
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2009-01-01
This paper details the combination of heart rate, core body temperature, and actigraphy in an ambient daily living environment to enhance the understanding of the overall physiology of the human body. Such research represents a new advancement in the area of physiological measurements. Measurement of a single physiological ...
Physiological Pharmacokinetics
J. Dyn. Sys., Meas., Control;JDS Volume 95 Issue 3 1973-09-01
This paper reviews the physiological bases of pharmacokinetics and discusses the use of physiological and biochemical information in developing compartmental models. Pharmacokinetic principles are illustrated by reference to published work on methotrexate distribution in several animal species. Use of pharmacokinetics in predicting drug effect is cited.
Mining physiological data for automated feedback in virtual learning environments
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2010-01-01
Authors present the great potential of data, obtained from real time physiological measurement, for immediate and individualized reaction on the learning process of the learning subject in virtual learning environments.
Establishment of New Electro-oculogram Measurement Technique by Integrating Virtual Instrument
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2009-01-01
In this research, a new electro-oculogram measurement technique is designed and constructed. The structure of virtual instrument built by software part, Labview hardware part, DAQ card and some external circuits is applied in the development process. This research integrates industry needing oriented technology - physiological measurement of medical industry, advanced technology - virtual ...
Prediction of Respiratory Measurements based on Cross Embedding Techniques
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2007-01-01
Measurements of multiple physiological signals are required for diagnostic procedures such as for sleep disordered breathing. Accuracy of automated diagnostic procedures and home based screening methods can be affected when physiological measurements contains artifacts or signal losses. We investigate on predicting one physiological ...
Regulation and Control in Physiological Systems
J. Dyn. Sys., Meas., Control;JDS Volume 97 Issue 2 1975-06-01
Abstract not available.
Proc. SPIE;PSI Volume 7160 Issue 1 2008-12-03
A human physiological parameters intelligent clothing is researched with FBG sensor technology. In this paper, the principles and methods of measuring human physiological parameters including body temperature and heart rate in intelligent clothing with distributed FBG are studied, the mathematical models of human physiological parameters measurement ...
Measurement of motion and emotion during musical performance
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2009-01-01
This paper describes the use of physiological and kinematic sensors for the direct measurement of physical gesture and emotional changes in live musical performance. Initial studies on the measurement of performer and audience emotional state in controlled environments serve as the foundation for three pieces using the BioMuse system in live performance. By using both motion and emotion ...
8×16 channel physiological monitoring platform of stem cell culture systems
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2006-01-01
An up to 128 channel PC-based physiological measurement platform for stem cell cultures is presented in this paper. The platform is designed to measure the most important stem cell culture parameters namely pH, temperature and glucose in real-time. The aim is to optimize the whole bioprocess by means of the acquisition of real-time, on-line, in-situ quantitative physiology ...
J. Biomed. Opt.;JBO Volume 14 Issue 6 2009-11-01
Accurate, unambiguous detection of molecular interactions in living cells via measurements of F[o-umlaut]rster (or fluorescence) resonance energy transfer (FRET) events is experimentally challenging. We develop and apply a physiological fluorescence lifetime imaging microscopy (physiological FLIM) system to significantly improve FRET detection in living cells. Multiple positive and negative ...
Design and Implementation of a Portable Long-Term Physiological Signal Recorder
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2010-01-01
This paper describes a design and implementation of a portable physiological signal recorder. The device is designed for measuring electrocardiography, bioimpedance, and user's activity. The bioimpedance measures the dynamic changes in the impedance, and its main application is monitoring user's respiration. Activity is measured with three-axis acceleration ...
Physiological Optics at the National Bureau of Standards
, Vol. 6 Issue 1, pp.13-26 (1967) 1967-01-01
Published work in physiological optics at the National Bureau of Standards is summarized under the headings: evaluation of light-dark patterns, light measurements, color measurement, color differences, and color perception. The bearing of this work on standard methods of the American Society of Testing and Materials, of the Illuminating Engineering Society, and of the American Standards ...
Editorial: Outgoing Editor-in-Chief
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2007-12-01
As this is my last issue as Editor-in-Chief of Physiological Measurement, I would like to reflect on the past six years and look ahead to the bright future for this publication. There have been many changes to this journal in recent years. We have gone from a quarterly publication to one that appears monthly, and our annual number of published pages has almost tripled. The number of manuscripts received and papers published ...
Editorial: Outgoing Editor-in-Chief
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2007-12-01
As this is my last issue as Editor-in-Chief of Physiological Measurement, I would like to reflect on the past six years and look ahead to the bright future for this publication. There have been many changes to this journal in recent years. We have gone from a quarterly publication to one that appears monthly, and our annual number of published pages has almost tripled. The number of manuscripts received and papers published ...
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2003-08-01
The authors present a new non-intrusive experimental procedure based on laser techniques for the measurement of mechanical properties of tendons. The procedure is based on the measurement of the first resonance frequency of the tendon by laser Doppler vibrometry during in vitro tensile experiments, with the final aim of establishing a measurement procedure to perform the mechanical characterization ...
Blood vessel diameter measurement on ultrasonic images
Proc. SPIE Int. Soc. Opt. Eng.;PSI Volume 5637 Issue 1 2005-02-08
Accurate measurement of blood vessel diameter on ultrasonic images is a potential part in diagnosis and physiological study. In this paper, a method of blood vessel diameter measurement has been presented. In our approach, we firstly used a histogram equalization technique to enhance the contrast of ultrasonic images. Secondly, a Guassian filter is used to remove the noisy pixels while preserving ...
OCT system for plant measurement
Proc. SPIE Int. Soc. Opt. Eng.;PSI Volume 5948 Issue 1 2005-09-16
An Optical coherence tomography system (OCT system) was developed to measure physiological response inside plant. This system has a unique optical scanner of wide scanning range of 40mm to adapt the OCT measurement to irregular features and many breeds of plant samples. To use in the outdoor field, which plants volunteers, the system should be compact, stable, and have high repetition frequency ...
Evaluation of Phase Signals in Quantitative Near-Infrared Spectroscopy
, Vol. 35 Issue 13, pp.2248-2250 (2010)
We study the effect of continuous phase measurement on the estimation of concentration changes in quantitative near-infrared spectroscopy. We also assess the sensitivity of phase signals on the estimation of physiological changes in tissue.
Evaluation of Phase Signals in Quantitative Near-Infrared Spectroscopy
, Vol. 24 Issue 21, pp.3666-3672 (1985)
We study the effect of continuous phase measurement on the estimation of concentration changes in quantitative near-infrared spectroscopy. We also assess the sensitivity of phase signals on the estimation of physiological changes in tissue.
Intrathoracic airway measurement: ex-vivo validation
Proc. SPIE Int. Soc. Opt. Eng.;PSI Volume 3033 Issue 1 1997-05-09
High-resolution x-ray CT (HRCT) provides detailed images of the lungs and bronchial tree. HRCT-based imaging and quantitation of peripheral bronchial airway geometry provides a valuable tool for assessing regional airway physiology. Such measurements have been sued to address physiological questions related to the mechanics of airway collapse in sleep apnea, the measurement ...
The Analytical, Control Systems Approach to Physiological Experimentation---the Hypertension Problem
J. Dyn. Sys., Meas., Control;JDS Volume 95 Issue 3 1973-09-01
Abstract not available.
Temperature measurement of the human body
Proc. SPIE Int. Soc. Opt. Eng.;PSI Volume 2779 Issue 1 1996-04-26
The information about physiological bases of warmth-radiation of a person is given and the opportunity of microwaves application of dielectrics aerials and dielectrics of resonators at measurements of temperature in the clinical diagnostics is considered.
Spherical Harmonic Spectra of Head-Related Transfer Functions
103 - Paper 4571 1997-09-01
We make use of representations known as Spherical Harmonic Spectra (SHSs) to illustrate these weight variations, and discuss the implications of the representation in terms of identifying physiological variations within the HRTFs, and in terms of the efficient measurement and encoding of HRTF data
Diffuse optical imaging of the whole head
J. Biomed. Opt.;JBO Volume 11 Issue 5 2006-09-01
Near-Infrared Spectroscopy (NIRS) and diffuse optical imaging (DOI) are increasingly used to detect hemodynamic changes in the cerebral cortex induced by brain activity. Until recently, the small number of optodes in NIRS instruments has hampered measurement of optical signals from diverse brain regions. Our new DOI system has 32 detectors and 32 sources; by arranging them in a specific pattern, we can cover most of the adult head. With the increased number of ...
Wireless body sensor networks for health-monitoring applications
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2008-11-01
Current wireless technologies, such as wireless body area networks and wireless personal area networks, provide promising applications in medical monitoring systems to measure specified physiological data and also provide location-based information, if required. With the increasing sophistication of wearable and implantable medical devices and their integration with wireless sensors, an ever-expanding range of therapeutic and ...
Experimental Investigation of Pulsatile Flows in Tubes
J. Biomech. Eng.;JBY Volume 119 Issue 2 1997-05-01
Based on cam-piston-valve arrangement, a mechanical pulsatile flow generator is designed to investigate sinusoidal flow and other types of pulsatile flow in straight rigid tube. Measurement reveals the relation between pressure gradient and flow rate. Numerical simulation using the k-epsilon turbulence model are carried out to compare the pulsatile flow produced by the generator with a sinusoidal flow and a physiological flow ...
Remarks about the depth resolution of heterodyne interferometers in cochlear investigations
J. Acoust. Soc. Am.;JAS Volume 110 Issue 4 2001-10-01
Criteria of depth resolution of interferometric vibration measurements in the cochlea are discussed. Depending on the aim of the measurement, attention should be directed to the outer flank of the interference visibility curve, in contrast to the usual criterion of full width at half maximum. The depth at 30 dB suppression is proposed as a more appropriate criterion, when the measurement ...
Improved performance in diffuse reflectance measurement by polarization discrimination
Proc. SPIE Int. Soc. Opt. Eng.;PSI Volume 5630 Issue 1 2005-01-18
Previous research has shown that un-contact monitoring and characterization of diffuse reflectance photons emerged at the tissue surface could provide the useful physiological parameters within tissue to aid the diagnosis. Generally within this method, the detected optical signal consists of the specular reflection from the tissue surface and diffusive photons emerging from within tissue, while the latter being the signal of interest. However, the surface reflection ...
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2007-10-01
The pulsed Doppler method theoretically enables human arterial blood flow (BF) to be determined in all of the abdominal-pelvic organs (BFAP) by subtracting the bilateral proximal femoral arterial BF from the upper abdominal aorta BF above the coeliac trunk. Evaluation of BFAP is a potentially useful indicator of exercise or food intake related flow distribution to organs; however, there is a lack of information regarding the physiological significance of BFAP, ...
Methods of determination of acoustic data in field studies
J. Acoust. Soc. Am.;JAS Volume 105 Issue 2 1999-02-01
An interdisciplinary field study examining the annoyance by rail and road traffic noise with special regard to sleep disturbance was carried out. The noise induced responses were determined by questionnaires and physiological measurement of sleep disturbance. For subjects taking part in the physiological examination, acoustical measurements have been ...
J. Acoust. Soc. Am.;JAS Volume 80 Issue S1 1986-12-01
In recent years knowledge of the basic physiology of mechanoreceptors has advanced considerably. The translation of this knowledge into psychophysical threshold measurement techniques for assessing mechanoreceptor performance at the fingertip will be described. The sensitivity of three types of mechanoreceptors, the Pacinian corpuscles, Meissner corpuscles, and Merkel disks, is obtained from threshold measurements ...
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2004-10-01
Hydrocephalus is far more complicated than a simple disorder of CSF circulation. Historically, it has been diagnosed using clinical and psychomotor assessment plus brain imaging. The role of physiological measurement to aid diagnosis becomes more appreciated in current clinical practice. This has been reflected by recently formulated guidelines for the management of normal pressure hydrocephalus. Clinical measurement ...
An Investigation of Particle Flow Through Capillary Models With the Resistive Pulse Technique
J. Biomech. Eng.;JBY Volume 109 Issue 2 1987-05-01
The use of the resistive pulse technique for the measurement of microsphere and red cell transit times through single-pore ``Nuclepore'' membranes (with pore diameters of 3.5 to 7.0 mu m and pore length of approximately 11 mu m) is described. The investigation of the fluid mechanics and electrical characteristics of the experimental system provides methods for the determination of particle and cell size, and entrance and transit times. Experimental measurement ...
A real-time heat strain risk classifier using heart rate and skin temperature
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2008-12-01
Heat injury is a real concern to workers engaged in physically demanding tasks in high heat strain environments. Several real-time physiological monitoring systems exist that can provide indices of heat strain, e.g. physiological strain index (PSI), and provide alerts to medical personnel. However, these systems depend on core temperature measurement using expensive, ingestible thermometer ...
Modified String Flowmeter for Measuring Breath Velocity
Rev. Sci. Instrum.;RSI Volume 20 Issue 6 1949-06-01
An instrument is described which measures instantaneous breath velocities without incurring high flow resistances. It records reciprocating flows, such as those of the full breath cycle, within the limits of normal breath velocities with high frequency resolution and yields accurate and reproducible measurements when suitably calibrated. The system described incorporates an automatic control over a valve system insuring directed ...
Rev. Sci. Instrum.;RSI Volume 55 Issue 2 1984-02-01
A new technique for the measurement of Raman spectra of small particles in suspension, such as biological cells, is described. The particles flow through a rectangular glass capillary mounted at the sample position of a laser Raman microspectrometer. The measuring volume inside the glass capillary is comparable to the volume of the particles. The elastic forward light scattering of the laser beam by the particles is used to ...
Nonlinear refraction in vitreous humor
, Vol. 18 Issue 21, pp.1792-1794 (1993) 1993-11-01
We extend the application of the z-scan technique to determine the nonlinear refractive index (n2) for human and rabbit vitreous humor, water, and physiological saline. In these measurements there were nonlinear contributions to the measured signal from the aqueous samples and the quartz cell that held the sample. Measurements were ...
Chance correlation in non-invasive glucose measurement using near-infrared spectroscopy
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2005-08-07
Although the non-invasive glucose measurement technique based on near-infrared (NIR) spectroscopy has been an active research area for over twenty years, a reliable monitoring method has not been established yet. The key problem is that the spectral variations due to glucose concentration are extremely small compared to that from other biological components. In addition, there are also some ambiguous time-dependent physiological ...
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2006-12-01
Each year the Editorial Board of Physiological Measurement has the task of choosing the paper published in the previous year that represents the most significant advancement in physiological measurement science and/or technology. This is a particularly difficult endeavor, for there are many deserving manuscripts published. Not only that, major impact ...
Novel approaches to the measurement of arterial blood flow from dynamic digital X-ray images
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2005-01-01
We have developed two new algorithms for the measurement of blood flow from dynamic X-ray angiographic images. Both algorithms aim to improve on existing techniques. First, a model-based (MB) algorithm is used to constrain the concentration-distance curve matching approach. Second, a weighted optical flow algorithm (OP) is used to improve on point-based optical flow methods by averaging velocity estimates along a vessel with weighting based on the magnitude of ...
Applications and Techniques of Inners to Stability, Analysis, and Synthesis
J. Dyn. Sys., Meas., Control;JDS Volume 97 Issue 3 1975-09-01
Recently, E. I. Jury has developed an analysis method for linear systems based on the concept of Inners. His approach uniformly treats both continuous and discrete systems while being computationally simpler than previous techniques. The aim of this paper is to introduce and explain some of the more general applications of the Inners method to problems in stability, analysis, and synthesis of linear systems.
Neutral Points in 138 Protanopes and Deuteranopes
, Vol. 46 Issue 8, pp.640-649 (1956) 1956-08-01
Neutral points have been found by means of a rotary mixer and Munsell papers, minimizing any dispersion of individual values by individual ocular pigmentations. Determined thus, the Illuminant C values for 39 new (post-Walls-Mathews) protanopes covered a range of 3.7 mµ with the mean at 492.3 mµ, those for 38 new deuteranopes a range of 5.8 mµ with the mean at 498.4 mµ.Illuminant D values for 13 additional protanopes covered a range of only 3.3 mµ with the mean at 490.3 mµ, those for 15 recent ...
Colorimetry in optical coating
Proc. SPIE Int. Soc. Opt. Eng.;PSI Volume 5963 Issue 1 2005-09-30
Generally, the colour of the non-luminous objects in nature is due to absorption, diffusion and refraction of light. The colour of the optical coatings, as that of some kind of bird feathers, soap bubbles, butterfly wings, some insects, etc. is due to interference and therefore is named interference colour. This kind of colour belongs to the gonio-apparent or special-effect colours. Generally, industrial colorimetry does not deal with interference colour and the usual colorimetric instruments are ...
Proc. SPIE Int. Soc. Opt. Eng.;PSI Volume 6630 Issue 1 2007-07-05
The intrinsically ordered arrays of proteins in skeletal muscle allows imaging of this tissue by Second Harmonic Generation (SHG). Biochemical and colocalization studies have gathered an increasing wealth of clues for the attribution of the molecular origin of the muscle SHG signal to the motor protein myosin. Thus, SHG represents a potentially very powerful tool in the investigation of structural dynamics occurring in muscle during active production of force. A full characterization of the polarization-dependence ...
: 22nd International Conference: Virtual, Synthetic, and Entertainment Audio - Paper 000218 2002-06-01
to improve the classical transform based psychoacoustics model to better suit the physiological ear model, which is more accurate in approximating the masking threshold obtained from the psycho acoustical measurement. The linear additivity assumption for simultaneous masking is identified as main
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 1999-01-01
The design and implementation of a system for the automated and continuous in situ monitoring of the dielectric constant of woody vegetation tissue are presented. The implementation of both single-channel and multichannel systems is discussed. These systems permit unsupervised continuous and long-term monitoring of vegetation canopy dielectric behavior in remote field sites. Utilizing open-ended coaxial lines, the real and imaginary parts of the microwave dielectric constant of woody plant tissue ...
A Combined Heat Clearance Method for Tissue Blood Flow Measurement
J. Biomech. Eng.;JBY Volume 113 Issue 4 1991-11-01
Tissue Blood Flow is measured by applying a combined procedure of two independent approaches based on heat clearance: the Pulse Decay Method and the Continuous Method. The Pulse Method allows absolute assessment of tissue BF with no need for calibration, and can be applied only if the tissue BF is steady during the period of measurement. On the other hand, the Continuous Method enables the observation of rapid changes in tissue ...
Sonic Gas Analyzer for Measurement of CO[sub 2] in Expired Air
Rev. Sci. Instrum.;RSI Volume 28 Issue 11 1957-11-01
A sonic gas analyzer intended primarily for estimation of CO[sub 2] in the physiological range of 0--10% is described. The instrument uses a resonant cavity maintained in oscillation by a transistor amplifier as the measuring device; the change in frequency caused by the presence of CO[sub 2] in the cavity is linearly related to the amount of CO[sub 2] present. As described the instrument is intended for continuous sampling ...
Noncontact MMG Sensor Based on the Optical Feedback Effect in a Laser Diode
J. Biomed. Opt.;JBO Volume 3 Issue 3 1998-07-01
An optical interferometric MMG sensor is presented. It uses the feedback effect in a laser diode to measure the vibration generated by the MMG at the skin surface. Its key features are noncontact measurement, high sensitivity, and extended bandwidth toward low frequencies ([approximate] 1 Hz). Furthermore, as it is able to recover with a good accuracy the shape of vibrations ranging from 1 mu m peak-to-peak, the MMG is expressed ...
A rigorous examination of the real-ear attenuation at threshold method (125 Hz--2 kHz)
J. Acoust. Soc. Am.;JAS Volume 71 Issue S1 1982-04-01
The most ubiquitous method of measuring the attenuation of hearing protection devices (HPDs) is that of real-ear attenuation at threshold (REAT). Such tests, which evaluate the hearing thresholds of human subjects both with and without the HPDs in place, have often been criticized for measurement artifact and inappropriate test conditions. We examined two of the more common alleged REAT problems; masking of the occluded thresholds ...
Speech intelligibility in rooms
J. Acoust. Soc. Am.;JAS Volume 101 Issue 5 1997-05-01
Speech is a method of communication between two or more minds. The actual forming and understanding of the message are in the physiological domain. The transmission of the speech by sound waves is in the physical domain. Only the latter can be controlled by means of acoustical engineering. The relevant processes in the physiological domain can be contained in the term ``proficiency of speaker and listener.'' The relevant processes ...
Minimally Invasive Electrical Impedance Measurements of Ovum Exemplified Using Microelectrodes
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2007-01-01
It is commonly accepted that electrical impedance provides relevant information about the physiological condition of living tissues. Currently, impedance measurements are performed with relatively large surface electrodes not suitable for studies in micro tissue due to their poor spatial resolution and high ESEI that they cause on the surface of skin. A minimally invasive electrical impedance measurement ...
Proc. SPIE Int. Soc. Opt. Eng.;PSI Volume 5859 Issue 1 2005-06-30
Near-infrared spectroscopy (NIRS) is used for the non-invasive measurement of muscle oxygenation during an incremental cycle test in healthy volunteers. A broad band spatially resolved system is used that allows the reliability of current algorithms to be inspected with the main emphasis on tissue oxygen saturation (SO[sub 2]) and oxygenated and deoxygenated haemoglobin concentrations. Physiological conditions were modulated ...
Physiological aspects of the glottal sound generator
J. Acoust. Soc. Am.;JAS Volume 64 Issue S1 1978-11-01
This paper describes the function of laryngeal muscles in regulating the glottal sound generator. The glottal sound generator, i.e., the vocal fold, has a layered structure. From the anatomical point of view, one can differentiate five layers, all having different mechanical properties [M. Hirano et al., J. Acoust. Soc. Am. [bold 58], S13 (1975)]. From the physiological point of view, the layers may be divided into two major categories: the outer layer, i.e., ...
Fiber optic and time-resolving techniques in forest decline research
Proc. SPIE Int. Soc. Opt. Eng.;PSI Volume 1269 Issue 1 1990-08-01
Three novel techniques of fiber-optic spectroscopy have been recently introducedinto research of forest decline. These include measurement of luminescence changesand fluorescence-decay of chiorophylls (i) under continuous irradiation, and afterpulse-induction in the (ii) long-term and the (iii) picosecond time range. These changes will be correlated both with environmental factors such as air pollutants, soil,fertilization and various experimental and
Pistonphone Calibration of Microphones at Infrasonic Frequencies
J. Acoust. Soc. Am.;JAS Volume 37 Issue 6 1965-06-01
The application and development of microphones for measurement of sonic-boom phenomena, studies involving atmospheric turbulence, and physiological investigations have placed increased emphasis on accurate calibration at infrasonic frequencies. To establish microphone response at extremely low frequencies with a very significant level of accuracy, investigations revealed that the pistonphone provided the only practical technique. ...
Optical polarimetry applied to the development of a noninvasive in-vivo glucose monitor
Proc. of SPIE;PSI Volume 3923 Issue 1 2000-05-31
The application of optical polarimetry, using the anterior chamber of the eye as the sensing site, is being investigated as a potential method to develop a noninvasive physiological glucose monitor. First, we present results characterizing the optical rotatory dispersion of the main optically active analytes found within the aqueous humor of the eye including, glucose, albumin, and ascorbic acid. This information is used in conjunction with multiple linear regression ...
A Large-Scale Model of the Human Cardiovascular System and its Application to Ballistocardiography
J. Dyn. Sys., Meas., Control;JDS Volume 94 Issue 3 1972-09-01
Bond graphs have been used to construct a distributed-parameter model of the human cardiovascular system. The model includes the heart and arterial, capillary, and venous segments of both the pulmonary and systemic circulations. Anatomical and physiological data were utilized in implementing the model on a large digital computer. Comparisons of simulated output and measured responses are shown. Because a general-purpose bond ...
Phase-Sensitive Optical Low-Coherence Reflectometry for the Detection of Analyte Concentrations
, Vol. 43 Issue 17, pp.3408-3414 (2004) 2004-06-10
Optical techniques may potentially be used for noninvasive glucose sensing. We investigated the application of phase-sensitive optical low-coherence reflectometry (PS-OLCR) to the measurement of analyte concentrations. The dependence of the PS-OLCR signal on the concentration of various analytes, including aqueous solutions of glucose, calcium chloride, magnesium chloride, sodium chloride, potassium chloride, potassium bicarbonate, urea, bovine serum albumin, ...
Measurement of visual fat igue for large-sized TVs in a home viewing environment
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2009-01-01
The authors report here the result of the evaluation experiments that measured visual fatigue for large-sized TVs in a home viewing environment using 42-inch and 65-inch PDP displays by physiological and psychological measurements. Our results indicate that the optimum viewing distance for minimizing visual fatigue lies between 165 and 220 cm, a semi-absolute distance, rather than a strict ...
Micromachined piconewton force sensor for biophysics investigations
Appl. Phys. Lett.;APL Volume 89 Issue 17 2006-10-23
We describe a micromachined force sensor that is able to measure forces as small as 1 pN in both air and water. First, we measured the force field produced by an electromagnet on individual 2.8 mu m magnetic beads glued to the sensor. By repeating with 11 different beads, we measured a 9% standard deviation in saturation magnetization. We next demonstrated that the sensor was fully functional ...
Measurement method for image stabilizing systems
Proc. SPIE Int. Soc. Opt. Eng.;PSI Volume 6502 Issue 1 2007-02-15
Image stabilization in digital imaging continuously gains in importance. This fact is responsible for the increasing interest in the benefits of the stabilizing systems. The existing standards provide neither binding procedures nor recommendations for the evaluation. This paper describes the development and implementation of a test setup and a test procedure for qualitative analysis of image stabilizing systems under reproducible, realistic conditions. The basis for these conditions is provided by ...
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2007-01-01
Personal robots and robot technology (RT)- based assistive devices are expected to play a major role in Japan's elderly-dominated society, both for joint activities with their human partners and for participation in community life. These new devices should be capable of smooth and natural adaptation and interaction with their human partners and the environment, should be able to communicate naturally with humans, and should never have a negative effect on their human partners, neither physical nor ...
In vivo blood lactic acid monitoring using microdialysis and surface-enhanced Raman spectroscopy
Proc. SPIE;PSI Volume 7040 Issue 1 2008-08-28
Blood lactic acid concentration is an important indicator for physiological functions. To develop a rapid and sensitive measurement technique for monitoring blood lactic acid may provide a useful tool in clinical diagnosis. We proposed to develop a microdialysis surface-enhanced Raman spectroscopy (microdialysis-SERS) approach to filter/reduce interference from other large metabolites in blood and enhance the detection sensitivity ...
Rev. Sci. Instrum.;RSI Volume 71 Issue 1 2009-01-01
Work has been intensified around the integration of textile and measurement technology for physiological measurements in the last years. As a result nowadays it is possible to find available commercial products for cardiovascular personal healthcare monitoring. Most of the efforts have been focused in the acquisition of EKG for cardiovascular monitoring where textile electrodes have shown ...
, Vol. 29 Issue 17, pp.2031-2033 (2004) 2004-09-01
We extend second-harmonic generation (SHG) microscopy to the measurement of sarcomere length in unstained living cardiac myocytes with 20-nm accuracy. We quantify individual sarcomere shortening in the presence of saxitoxin and find that it is in agreement with mechanical measurements of atrial tissue contracture. This functional application of SHG microscopy is generally applicable to quantify the physiological ...
Automatic Control of Human Thermal Comfort by a Liquid-Cooled Garment
J. Biomech. Eng.;JBY Volume 102 Issue 2 1980-05-01
Astronauts utilize water cooling in a liquid-cooled garment to maintain thermal comfort during extravehicular activities (EVA's). In the Apollo and Skylab Programs, manual control of the cooling water was a necessary operation to ensure proper control of body heat storage for the EVA crewman. The development of an automatic thermal control system would be a valuable asset to the conduct of EVA, relieving the crewman of a task that can interfere with his EVA objectives. An analytical model of human ...
Biochemical measurement of bilirubin with an evanescent wave optical sensor
Proc. SPIE Int. Soc. Opt. Eng.;PSI Volume 1510 Issue 1 1991-09-01
Optical sensing techniques can be considered as powerful information sources on the biochemistry of tissue, blood, and physiological fluids. Various sensing modalities can be considered: spectroscopic determination of the fluorescence or optical absorption of the biological medium itself, or more generally, of a reagent in contact with the biological medium. The principle and realization of the optical sensor developed are based on the use of polished fibers: ...
The Measurement of Heat Production in Diathermy
Physics;JAP Volume 4 Issue 10 1933-10-01
Resistance and reactance of diathermy patients to alternating currents of varying frequencies up to and including radiofrequencies have been measured with a high frequency Wheatstone bridge. At frequencies greater than one million cycles per second the resistance becomes constant and the reactance and phase angle decrease to zero. Under these conditions the human body behaves as a pure resistance and the heat production in calories can be computed from the formula ...
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