United States Patent m
Schal
[li] Patent Number: [45] Date of Patent:
[54] APPARATUS FOR THE TREATMENT OF BLOOD IN PARTICULAR FOR HEMODIALYSIS AND HEMOFILTRATION
[75] Inventor: Wilfried Schal, Bad Homburg, Fed. Rep. of Germany
[73] Assignee: Fresenius AG, Fed. Rep. of Germany
[21] Appl. No.: 209,678
[22] Filed: Jun. 21, 1988
[30] Foreign Application Priority Data
Jun. 23, 1987 [DE] Fed. Rep. of Germany 3720665
[51] Int. CI.' B01D 13/00; B01D 35/00
[52] U.S. CI 210/87; 210/90;
210/137; 210/143; 210/321.65; 210/929; 604/5
[58] Field of Search 210/87, 90, 137, 143,
210/321.65, 321.71, 929; 604/4, 5
[56] References Cited
U.S. PATENT DOCUMENTS
3,946,731 3/1976 Lichtenstein 210/929
4,021,341 5/1977 Cosentino et al 210/321.65
4,145,925 3/1979 Stasz et al 128/662.01
4,147,059 4/1979 Fathauer 128/662.01
4,509,528 4/1985 Sahota 128/691
4,542,644 9/1985 Claytor et al 73/599
4,596,549 6/1986 Minami 210/140
4,711,715 12/1987 Polaschegg 210/137
4,718,890 1/1988 Peabody 604/65
4,735,727 4/1988 Hettmeier et al 210/87
4,747,822 5/1988 Peabody 604/29
Primary Examiner—W. Gary Jones
Attorney, Agent, or Firm—Townsend and Townsend
[57] ABSTRACT
The apparatus for hemodialysis and hemofiltration comprises an extracorporeal blood circuit comprising a dialyzer and/or filter arrangement. For determining the fluid withdrawal per unit time and the total amount of fluid withdrawn flow sensors in conjunction with an evaluating unit are inserted into the blood circuit upstream and downstream of the dialyzer or filter arrangement. The flow measurement is by the ultrasonic Doppler principle and for obtaining high accuracy the sensors comprise measuring inserts belonging to the blood tubing system and having special means for defined coupling-in and coupling-out and precise conduction of the ultrasonic waves. Apart from the measurement, means are provided for regulating the net fluid withdrawal.
22 Claims, 5 Drawing Sheets
