A portable, real-time, clinical gait velocity analysis system

A direct ultrasound ranging system (DURS) has been developed for the quantitative evaluation of gait velocity. DURS consists of a transponder worn by the subject, a base unit infrared (IR) emitter/ultrasound (US) receiver, and a laptop computer. During gait analysis the transponder is worn by the subject at the approximate level of the body center of mass. As the subject walks away from the base unit his or her forward progression is displayed in real-time on the computer. At the end of the walking trial the instantaneous velocity profile, or gait velocigram (GVG), for that trial is displayed on the computer screen. From the GVG, parameters such as, gait speed, cadence, step length, step time, peak-to-peak variation, and time to achieve steady state walking are calculated and displayed. In addition gait deviations are readily apparent on the GVG.     

A portable magnetometer

A portable magnetometer to determine magnetic field anomalies is described. The block diagram of the magnetometer and its specifications are presented.     

Choosing the right clinical camera. Part II

From a practical standpoint, both ring and dual flash are easier to control for the operator. It is not necessary to remember to put the flash on the side of the mirror or to rotate the flash to avoid unwanted shadows. The point source flash requires a learning curve and the dual point source flash, away from the lens, has limited applications. The lighting quality brings out the third dimension in photography and is therefore among the most important factors when taking image quality into consideration. The dual source flash on the lens system provides a more pleasing and natural illumination than the other systems. The Nikon SB21-B fulfills these requirements while offering the possibility to be used as a single source flash unit. Furthermore, the flash unit's close proximity to the lens allows the light to reach virtually any area in the mouth. Lastly, the TTL option takes care of the concern regarding the consistency of the light intensity and significantly speeds up the recycling time.     

Choosing the right clinical camera. Part I

Our recommendation is a 90-105 mm macro lens focusing from 1:1 to infinity and a minimum aperture of f/32. A reputable brand should be preferred: Nikon, Canon, Minolta, Sigma etc.... A 105 mm macro lens allows for adequate working distance (approx. 130 mm for a straight view at 1:1 magnification). A 105 mm macro lens induces insignificant perspective distortion and has a large range of aperture. Lastly, it provides for a magnification scale ranging from 1:1 to infinity and is optically excellent. The working distance of current camera systems extends approximately from 4 4/8" or 114 mm, to 7" or 180 mm, at 1:1 magnification. Again these differences are mainly due to lens design and mounted components, (filters, bracket, lighting systems). A minimum of 5" or 125 mm of working distance is desirable for physical access of your camera and proper illumination of the photographed object. However, adequate lighting also depends upon the type and location of your lighting system especially for higher magnification photographs. Part II will examine the different lighting systems on the market and try to decide which is most adapted to your needs. It will answer your questions about the use of the operatory light while focusing, the red eye problem and the use of polarizing filters to decrease the amount of reflection from the flash.     

A portable blood gas analyzer for equine venous blood

Evaluation of a portable blood gas analyzer, (StatPal II, Unifet, Inc, La Jolla, CA) was performed using tonometered solutions and equine blood. Samples were analyzed by the StatPal II and either an Instrument Laboratory IL1306 (Lexington, MA) or a Radiometer ABL50 blood gas analyzer (Radiometer America Inc., Westlake, OH). Comparison of the StatPal II and the IL1306 was done by analysis of 3 tonometered solutions (acidic, normal, and alkalotic) and 27 equine venous blood samples. Blood pH, PCO2, PO2, and [HCO3] values were altered by IV infusion of 5% sodium bicarbonate or exercising the horses on a treadmill. Comparison of the StatPal II and the Radiometer was performed by analysis of 78 blood samples collected from Standardbred horses before a race. Data were analyzed for the venous blood samples using a paired two-tailed Student's t test and Bland-Altman plots, with significance set at P < .05. The coefficients of variation for pH, Pco2, Po2, and [HCO3-] values of the tonometered solutions analyzed by the StatPal II ranged from 0.067% to 0.087%, 2% to 3.21%, 1.21% to 2.67%, and 0.267% to 0.828%, respectively. Comparison of the equine blood samples analyzed by the StatPal II and the IL1306 demonstrated statistically significant, but clinically irrelevant differences in pH, Pco2, and Po2, but not [HCO3-]. There were statistically significant, but clinically irrelevant differences between the StatPal II and the Radiometer for pH, Pco2, and [HCO3-], but not for Po2. It is concluded that the StatPal II provides reproducible and acceptable analysis of equine venous blood gas samples.     

A neutron television camera detector

The system under development has a large counting rate capability; this is extremely important where the total background count exceeds the total counts in the signals of interest. Its spatial resolution is of the order of one mm, which is perfectly adequate for neutron work, while the screen size of 400 mm is reasonable. The main limitation of the system is its limited counting efficiency, and this is directly attributable to the optical self-absorption of the neutron phosphor. Any newly developed transparent phosphor with the same light output would immediately change the situation. The success of the electronics hardware in reducing random noise is demonstrated in Figure 3, which shows in the bottom trace the live video output when the input to the system is a grey-scale test chart. The top trace is the output after the image has been digitally integrated. Figures 4 and 5 show the monitor outputs of the see articles x-ray system with a "still" diffraction pattern of a crystal of GPD (glyceraldehyde-3-phosphate dehydrogenase). Figure 4 is a photograph of the "live" video display, and Figure 5 is the digitally summed image. All coherent noise in the system, i.e., all noise synchronized with the TV scans has to be kept lower than the first bit threshold. However, this requirement can be relaxed when dealing with diffraction patterns, such as those from single crystals, for which a local background is subtracted from the pattern.     

A portable vapor/particle sampler

The airborne particle and vapor phases of a volatile organic chemical (VOC) often coexist in the real workplace environment. Assessment of worker exposure to a VOC requires measuring not only the total airborne concentration but also the phase distribution because the deposition efficiency of the material in the respiratory tract will depend on the form in which it is inhaled. A prototype portable vapor/particle sampler (PVPS) has been designed for sampling and quantifying the phase distribution of volatile components in micrometer-sized airborne particles and coexisting gaseous phase based on differential inertia. The sampler was laboratory tested and validated. Tests included sampler performance assessment and comparison with current sampling methods for particles and organic vapors, i.e., glass fiber filter, charcoal sorbent tube, and diffusion monitors. The PVPS is a low-cost and lightweight device that can be driven by a single standard personal sampling pump. The mass quantities of materials collected by the sampler can be determined by standard analytical procedures. Combined with an appropriate size-selective inlet, the PVPS may be used as a personal inhalable or respirable volatile aerosol sampler for occupational VOC exposure assessment, especially in industrial, or household, spray work environments where the particle sizes are frequently large.     

The wick catheter technique for measurement of intramuscular pressure. A new research and clinical tool

The wick catheter technique was developed in 1968 for measurement of subcutaneous pressure and has been modified for easy intramuscular insertion and continuous recording of interstitial fluid pressure in animals and humans. Studies in dogs of the anterolateral compartment of the leg in simulation of the compartment syndrome showed the technique to be accurate and reproducible. The wick catheter technique is capable of important clinical applications in the diagnosis and treatment of acute and chronic compartment syndromes.     

Development of instrumental and technical measurement aspects for clinical capillary microscopy

Clinically oriented investigation in microcirculation was stimulated by the internist O. Müller. After the second World War new electronic methods were established and later converted into clinical techniques. Therefore it became possible to measure capillary blood cell velocity, dynamic capillary blood pressure and transcapillary diffusion of fluorescent tracers in human skin. For many years vital capillaroscopy has been successfully used to study the microcirculation of human skin capillaries. Capillary video-microscopy at the finger nailfold in connection with local cold exposure test are presented as a method with clinical applicability in vasopastic disease.     

A miniature CCD video camera for high-sensitivity light measurements in freely behaving animals

A gas chromatography-combustion-isotope ratio mass spectrometry method for confirmation of hydrocortisone abuse in horseracing and equine sports is proposed. Urinary hydrocortisone was converted to a bismethylenedioxy derivative which presents good gas chromatographic properties and brings an extra carbon contribution of only two carbon atoms. Synthetic hydrocortisone has a different 13C abundance from that of natural urinary horse hydrocortisone and the difference is significant, therefore exogenous and endogenous hydrocortisone can be distinguished.     

The meanings and measurement of clinical significance.

The previous articles in this special section (P. C. Kendall et al, see record 1999-03648-001; N. S. Jacobson et al, see record 1999-03648-002; S. L. Foster and E. J. Mash, see record 1999-03648-003; and M. M. Gladis et al, see record 1999-03648-004) make the case for the importance of evaluating the clinical significance of therapeutic change, present key measures and innovative ways in which they are applied, and more generally provide important guidelines for evaluating therapeutic change. Fundamental issues raised by the concept of clinical significance and the methods discussed in the previous articles serve as the basis of the present comments. Salient among these issues are ambiguities regarding the meaning of current measures of clinical significance, the importance of relating assessment of clinical significance to the goals of therapy, and evaluation of the construct(s) that clinical significance reflects. Research directions that are discussed include developing a typology of therapy goals, evaluating cutoff scores and thresholds for clinical significance, and attending to social as well as clinical impact of treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The measurement of hostility in clinical situations.

"This study attempted to formulate operational definitions for the various meanings of the concept of hostility. Thirty men and thirty women, patients in a neuropsychiatric hospital, were interviewed and rated by three judges for the following aspects of hostility: Resentment, Verbal hostility, Indirect hostility, Assault, Suspicion, Over-all hostility, and Strength of hostile urges. Also, the Iowa Hostility Inventory was administered. It was found that the judges' ratings of the various aspects of hostility showed general agreement." (PsycINFO Database Record (c) 2010 APA, all rights reserved)