Samuel Bryan

Bio: Samuel Bryan is an academic researcher from Civil Aeronautics Administration. The author has contributed to research in topics: BALLISTOCARDIOGRAPH & Frequency response. The author has an hindex of 1, co-authored 1 publications receiving 8 citations.

The Low Frequency Velocity Measurement Ballistocardiograph

Abstract: The velocity measurement ballistocardiograph is described which has filter circuits to eliminate body tremor components. Small adjustable condensers are utilized on the input and output of the filter section to vary the frequency response of the circuit and thus create a sharper cut-off for occasional cases with high amplitude body tremor. The input and output condenser values are not above 5 mfd. in either section. By utilizing this type of circuitry, the lack of wave distortion makes it feasible to measure the ratios of wave amplitudes. The timing device makes it practical to time wave segments from the peak of the R wave, and a single channel recorder can be utilized. Normal standards are described and deviations from normal in coronary artery disease are discussed. The low frequency, velocity measurement ballistocardiograph is easily adaptable for routine office use.

[Ballistocardiography; an appraisal of technic, physiologic principles, and clinical value].

Abstract: T HE various modalities used in the study of the heart and circulation contribute different types of information. Some, such as electrocardiography and fluoroscopic or roentgenographic study, have such broad spheres of usefulness that they are almost routinely employed. Other diagnostic procedures have not gained wide usage either because of expense of equipment, difficulty in clinical application, specialized nature and limited value of information provided, or because such information as is provided unnecessarily duplicates what may be learned in simpler fashion. It is the object of this survey to appraise the clinical usefulness of ballistocardiography, a technic which records the movements imparted to the body by the forces associated with contraction of the heart, and acceleration and deceleration of blood as it is ejected and moved in the large vessels. Parenthetically it may be remarked that the ballistocardiogram provides, in simple and routinely applicable fashion, a considerable body of useful information not otherwise obtainable; and hence fulfills the criteria of a valuable adjunct in examination of the heart.

Acceleration Ballistocardiography: Design, Construction, and Application of a New Instrument

Abstract: The construction of a linear accelerometer for use in ballistocardiography is presented including the relationship between acceleration, displacement, and velocity. The sensing element described is new in the field of ballistocardiography, being based on an electrochemical principle. A means of easily calibrating the instrument is described, thereby allowing quantitative measurements of various components of the ballistocardiogram. Tracings of one abnormal and two normal individuals are illustrated to show the relationship between displacement and acceleration.

Present status of the ballistocardiogram.

Abstract: Excerpt The President of The American College of Physicians requested me to speak at the annual meeting and then to report in this journal on the present status of the ballistocardiogram, and so th...