Fatal Staphylococcus saprophyticus native valve endocarditis in an intravenous drug addict.
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Adult↗
Biomedical subjects
V R Singh
Publications and source records attributed to V R Singh.
A stress wave propagation technique for bone repair study.
The diagnosis of bone fracture and its rate of healing still remains a problem among orthopedic surgeons. An acoustic technique based on stress-wave propagation is developed. The technique is used on laboratory experimental in vitro bones, as well as on in vivo (human) bones, to diagnose a fracture. The rate of healing of the fracture is also studied. The technique developed is quick, economical, reliable, portable, and safe for both the patient and the operator.
Animals↗
Measurement of ultrasonic velocity and attenuation in bone tumors, in vitro.
Ultrasonic velocity and attenuation are determined in different types of bone tumors by using a double-probe-through-transmission ultrasonic technique. The average values of propagation velocity in different types of tumors are found as 2106, 2304, 2677.5, and 3586 m/s with 1.49%, 1.04%, and 0.74% standard deviation in Giant Cell, Lymphoma, Chondro Sarcoma, and Osteogenic Sarcoma, respectively. Absorption coefficient of ultrasound is found to be minimum as 19.7 dB/cm with 0.002% standard deviation in Lymphoma, and high in Osteochondroma and not measurable with the present setup. A direct technique for the diagnosis and differentiation of various types of tumors can be developed by standardization of the data.
Bone Neoplasms↗
Mechanical and ultrasonic parameters of kidney stones.
The mechanical and ultrasonic parameters of kidney stones have been measured in vitro. The techniques used for these measurements are briefly described and the data are presented. It was found that the mechanical crushing strength correlates with the acoustic velocity in the calculi, which in turn is a function of the stones' chemical deposition. It was shown that the crushing strength increased exponentially with velocity in the range from approximately 22 kg/mm2 to approximately 100 kg/mm2. The corresponding ultrasonic velocity in the stones varied between approximately 2,200 m/sec to about 3,000 m/sec. It is suggested that these data could be used to determine the desirable characteristics of a piezoelectric lithotripter.
Biophysical Phenomena↗
Ultrasonic studies of gall-bladder stones.
Measurements of ultrasonic speed, attenuation and other derived physical properties of gallstones, in vitro, have been evaluated and reported. A double-probe-contact through-transmission technique was used; the average values of ultrasonic speed and attenuation were found to be 1897 m s-1 and 10.2 dB cm-1, respectively, at 2.5 MHz (the value of speed thus being about 25% higher than that in water or soft biological tissues). The object of the present study was to determine the characteristics of stones to permit the optimization of a disintegrator design.
Bilirubin↗
Role of natural frequency of bone as a guide for detection of bone fracture healing.
The natural frequency of bone is studied in normal and fractured bones, in vitro as well as in vivo, by recording the outputs of microphone pick-ups, attached at proximal and distal ends to the bone defect. Natural frequency of bone is determined for an optimum output displayed on a cathode ray oscilloscope with respect to different stress wave frequencies. A comparative study of normal and fractured bone in vivo in 25 patients was made to diagnose the size of the fracture and its rate of healing. The natural frequency and intensity of sound in the injured bone was reduced while the output voltage increased with respect to the normal bone. The investigation reports a simple, reliable and rapid technique for the assessment of bone fracture.
Animals↗
Electromagnetic phenomena in bone.
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Bone and Bones↗
Acoustic power measurement of medical ultrasonic probes using a strain gauge technique.
A new method using a semiconductor strain guage is described for the measurement of the acoustic power output of ultrasonic medical therapy and other probe heads. The acoustic power output of the probe heads is found to be linearly related to the calibrated electrical output of the strain gauge transducer system, as expected theoretically. The instrument developed is inexpensive, portable and easy to operate for the routine measurement of ultrasonic output of the equipment in hospitals.
Calibration↗