Surgery – Blood drawn and replaced or treated and returned to body
Patent
1989-04-28
1992-06-09
Hafer, Robert A.
Surgery
Blood drawn and replaced or treated and returned to body
604 5, 604 51, A61M 103
Patent
active
051203030
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a method and apparatus for hemodialysis using a single needle, in which a predetermined volume of blood from a fistula, a vein or an artery is alternately drawn from the body of the patient to be filtered in an artificial kidney and then is returned to the patient at the same puncture location using a single, same needle.
The dialysis equipment comprises: kidney will hollow fibers; delivery and removal tube and provided in its upper part with an apical air tube intended for use as a pressure line and provided, a few millimeters lower, with an infusion line enabling the kidney to be rinsed, medication to be administered and the height of the blood level to be adjusted by means of air under pressure; chamber so as to absorb the periodic fluctuations in pressure produced by the varied filling of the expansion chamber; expansion chamber, the compliance chamber or the pressure line;
Hemodialysis is principally used in nephrology to treat acute as well as chronic renal inadequacies. This treatment consists of removing toxic substances from the blood in an external circuit using an artificial kidney based on the principle of the diffusion of the toxic substances through a semi-permeable membrane.
Patients must be connected two to three times per week to a semi-automatic artificial kidney at intervals generally of between two to three days on average. They remain connected to an artificial kidney for several hours by means of a shunt-needle or catheter and tubes in a synthetic material.
In conventional dialysis the blood flows in a given direction from side to side of an artificial kidney, that is from an arterial side to a venous side. The blood is removed from the circulatory system of the patient on the arterial side, through the catheter or through the dialysis needle, then driven by means of a pump in a determined direction in the artificial kidney, and ends up in an expansion vessel in which the pressure is recorded and the air bubbles collected, then to be returned into the circulatory system of the patient, in accordance with the following methods: if it is a two-needle system, the purified blood is returned at once through a second catheter or needle connected to the venous side, or, if it is a single puncture system, the purified blood is returned through a second pump or through a system of valves, to the first needle which is Y-shaped.
The first single-needle system is described by Kopp et al in an article entitled "Single needle dialysis"[and published in "Trans. Am. Soc. Art. Intern. Organs" No. 18, pages 75-80, 1972.
This system is the object of U.S. Pat. No. Re. 29,346 and U.S. Pat. No. 3,830,234.
The problem posed consists of drawing off and returning the blood to the same location. This implies technical difficulties with regard to the recirculation of the filtered blood, but has the incontestable advantage that it merely requires the introduction of a single needle.
This system contains a single pump segment and two solenoid valves on the arterial and venous blood line.
The valves are articulated in turn.
The blood is pumped from the circulator system of the patient, in particular from an artery, until a predetermined pressure is reached in the venous chamber. Once this pressure is reached, the arterial line is blocked and the venous line is opened.
The pump turns continuously in the same direction. In this manner, the blood is returned through the same needle at the same location into the circulatory system of the patient.
Due to the fact that the cycle is regulated by the fact of achieving a certain pressure and then by the passage of a certain time, this regulation is generally designated as the pressure-time system using a single needle. In 1979, Ahmad proposed a modification, by causing the valves to open and close for determined periods of time. He considered it useful to include three compressible pads of 10 ml each in the arterial circulatory system. A blood flow of 200 to 300 ml/min and a 5 second closing time were optimal. In addition to the advantage o
REFERENCES:
patent: 4235231 (1980-11-01), Schindler et al.
patent: 4490135 (1984-12-01), Troutner
patent: 4643714 (1987-02-01), Brose
patent: 4650457 (1987-03-01), Morioka et al.
patent: 4776837 (1988-10-01), Kopp
patent: 4828543 (1989-05-01), Weiss et al.
patent: 4867739 (1989-09-01), Kawano
Hafer Robert A.
Owens Kerry
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