John L. Nickerson

Diagnosis of Coarctation of the Aorta with the Aid of the Low Frequency, Critically Damped Ballistocardiograph

Ballistocardiograms taken with the low frequency, critically damped ballistocardiograph on 17 patients having coarctation of the aorta have a characteristic pattern in which the K wave is absent. In the patients in whom the coarctation was surgically removed, the pattern returned toward the normal type with reappearance of the K wave.

A study of the physical properties of the ballistocardiograph

Abstract Fourier analyses of the displacement ballistocardiograms of seven subjects recorded from four types of instruments have been made. The coefficients of these series were corrected for the distortion introduced by the ballistic bed and by transmission through the body. The coefficients representing the ballistic pattern from the four instruments were for each subject quite different in value in the corresponding terms. The effect of applying the corrections was to converge the coefficients of the corresponding terms of the series toward a common value. The common pattern thus predicted represents a basic acceleration pattern (or forcing function) and, by appropriate steps of integration, the associated velocity and displacement patterns. The coefficients of these basic series were compared with those of the original series obtained from the analyses of the patterns from the various instruments. This comparison was made in order to determine how closely the basic patterns are approximated by the records made by these instruments. The best agreement is between the pattern obtained from the low-frequency, critically damped ballistocardiograph and the basic velocity pattern. The next best correlation was between the high-frequency underdamped system and the basic acceleration pattern. It is also suggested from this research that the acceleration, velocity, and displacement can be represented with sufficient accuracy by Fourier series carried out to 11, 7, and 4 terms, respectively. This finding indicates, for example, that a ballistocardiograph adequate to represent the acceleration pattern must have a frequency response which is linear to 11 cycles per second and that adequate mechanical or electrical filtering must be present to eliminate the distortion introduced by the transmission of impulses through the body.

Abnormal ballistocardiographic patterns in cardiovascular disease as recorded with the low-frequency, critically-damped ballistocardiograph

Abstract Using a high frequency ballistocardiograph, Starr 1,2 has shown that certain abnormal patterns are associated with cardiac disease and that there is an improvement in the pattern of those individuals to whom digitalis is administered. In the present study of pattern abnormalities in disease, the low-frequency, critically-damped ballistocardiograph designed by Nickerson and Curtis 3 has been used because of the belief that it is a superior instrument. 4,5 It has been calibrated by Nickerson, Warren, and Brannon 4 against the method according to the Fick principle, using atrial catheterization. We have attempted to study the patterns qualitatively with the idea of (1) correlating pattern type with specific disease processes, and (2) correlating changes in a series of records with variations in clinical condition following treatment. As an example, we refer to the observations made in patients with coarctation of the aorta, in whom the pattern changes from an abnormal to a normal type after surgical removal of the constricted portion of the vessel. 6

A Study of the Transfer of Serum Proteins into Tissue Injured by Tourniquet.

Summary Electrophoretic, ultracentrifugal and immunochemical analyses of a protein extracted in buffered saline from tissues injured by the application of a tight tourniquet to one hind leg of the dogs indicate that large quantities of serum albumin enter the injured tissue. However, little or none of the α- and β-globulins enters the tissue. The dye, T-1824, injected intravenously before release of the tourniquet appears in the tissue of the injured leg only.

Application of the Transducer Tube to the Recording of the Peripheral Pulse

Summary This paper presents the application of the transducer tube to the detection and recording of movements of the type associated with the peripheral venous pulses. An adequate amplifier circuit is given and the usefulness of the device in other applications is suggested.

Postoperative changes in cardiac output

Abstract During the past three years, patients have been studied intensively from the standpoint of fluid, electrolyte, nitrogen, and caloric balance in the Surgical Metabolism Unit of the Presbyterian Hospital. Other physiological changes incident to operation have been recorded, among which is the cardiac output. This report records the study of cardiac output in the pre- and post-operative periods, as it varies with the condition of the patient, type of operation, and therapy. Starr and Mayock, 1 in 1945, recorded observations on cardiac output in relation to operation employing the high-frequency ballistocardiograph and noted that following simple herniorrhaphy, with the patient in the horizontal position, there was a decrease in cardiac output. In the more major operations, the same was true except when the patients received large amounts of fluids intravenously or when there was a larger protein and caloric intake. No significant difference was noted in cardiac output between patients having a herniorrhaphy who were kept at bed rest and those who exercised in bed or were allowed to walk early. However, the patients were first studied on the sixth postoperative day, and earlier changes might have been missed. Mayock and associates, 2 in 1946, reported from the same clinic on patients undergoing more serious operations, having a ballistocardiographic tracing made immediately, one, two, five, and ten days postoperatively. They noted that the average cardiac output was never significantly different from the value found before operation and that those patients in nitrogen equilibrium had less abnormality of the circulation after operation than those in negative balance. Hardy and Godfrey, 3 in 1944, employing Starrs ballistocardiograph measured the change in cardiac output in dehydrated patients given fluids intravenously and observed a significant increase, whereas such changes were not observed in the normal controls.