Methods and devices for characterizing tissues and the like utilize signals obtained from ultrasonic backscatter processes. The method accounts for frequency-dependent attenuation, spatially-varying media statistics, arbitrary beam geometries, and arbitrary pulse shapes. Statistical analysis is employed to estimate the scatterer number density (SND) of tissues. The method for estimating the scatterer number density incorporates measurements of both the statistical moments of the backscattered signals and the point spread function of the acoustic system.

Ultrasonic tissue characterization

Processing of plethysmographic signals via the cepstral domain is provided. In one embodiment, a cepstral domain plethysmographic signal processing method (200) includes the steps of obtaining (210) time domain plethysmographic signals, smoothing (220) the time domain plethysmographic signals, performing (230) a first-stage Fourier transformation of the time domain plethysmographic signals to frequency domain plethysmographic signals, computing (240) power spectrums from the frequency domain plethysmographic signals, scaling (250) the power spectrums with a logarithmic function, performing (260) a second-stage Fourier transformation on log-scaled spectrums to transform the power spectrums into cepstrums, and examining (270) the cepstrums to obtain information therefrom relating to a physiological condition of the patient such as the patient's pulse rate or SPO2 level.

Cepstral domain pulse oximetry

Apparatus for measuring intracranial pressure of a living body to be inspected utilizing ultrasonic waves. With this measuring apparatus, a probe which produces trigger signals is brought into contact with the cranium of the living body to be inspected so that ultrasonic pulses are introduced into the cranium for the frequency analyzation of the data on interfering waves being multi-reflected at the boundaries of tissues in the cranium to calculate and produce a time difference from among element waves of the interfered reflected waves. The apparatus is capable of measuring the thickness of the pachymeninx and a change thereof, as well as the intracranial pressure and a change thereof by utilizing a correlation between the intracranial pressure and the thickness of the pachymeninx. According to the conventional methods of measuring the intracranial pressure in most cases, the cranium was penetrated through. With the conventional method which admits no penetration through the cranium, on the other hand, the precision and cost were far from the practicable levels. The present invention has made it possible to easily measure the intracranium pressure from the outside of the cranium without penetrating it through and without adversely affecting the brain, maintaining safety and high reliability. Further, the measurement taken at regular intervals makes it possible to know the intracranial pressure and a pattern of change thereof, enabling the doctors to obtain proper data on diagnosis for the morbidity and to obtain preventive data on a change in a morbid state.

Apparatus for measuring intracranial pressure

The invention is the use of a chelating agent with an ultrasonic device for the treatment of hair and other fibers. The treatment device includes an ultrasound generator, a comb device responsive to the generated ultrasonic waves, a reflector for reflecting the incident ultrasonic waves disposed on the distal end of the comb device, and a chelating agent preferably disposed within the treatment device. The treatment device efficaciously dispenses the chelating agent and ultrasonically treats the fiber.

Method for the ultrasonic treatment of hair and other keratinous fibers

A method of determining in vivo an estimate of the modulus of elasticity of a bone. The method including the steps of applying an ultrasound beam to a limb from a transmitting transducer to a receiving transducer, and then measuring the flight times, Ts for an ultrasound beam along a first path through the cortex of the bone, and Tm along a second path through the cortex and medulla of said bone. After performing these steps, the method calculates the diameter X of the bone from the external diameter of the limb minus a predetermined constant allowing for skin and flesh, calculates the apparent velocity Ca from X divided by Ts, calculates the mean velocity V from X divided by Tm, and calculates the cortical bone velocity CbE from a predetermined function f multiplied by Ca. Next, the method determines a ratio R for the diameter of the medulla to the diameter of the cortex and then estimates the cross-sectional area CSAE of the bone from the values of the diameter X, the ratio R and from predetermined constants. From these derivations, the bone mineral content, BMC, the estimated compact bone density, CBDE, and an estimate of the modulus of elasticity from the product of CBDE and CbE are determined.

Method and apparatus for the measurement of bone quality in vivo

A diagnosis apparatus for discriminating a property of the tissue to be observed from the reflected ultrasonic wave uses the nature of the fine structure of the tissue, and more practically uses the interval of small reflecting bodies dispersely distributed in the tissue as the parameters. The intervals flucatuate. Therefore, an average value and/or a degree of fluctuation is calculated and is displayed. For obtaining the average interval, a method of using the cepstrum of the received signal or a method of using the self-correlation of the received signal can be used.

Michitoshi C O Fujitsu L Inoue

Papers

Ultrasonic diagnosis apparatus for tissue characterization