Ambulatory ultrafiltration device with control unit programmed to control a drive fluid pump to perform ultrafiltration

摘要

An ambulatory ultrafiltration device includes a blood filter that has a blood side or fluid communication with the vascular system of the subject, an ultrafiltrate side, and a semipermeable membrane disposed between the blood side and the ultrafiltrate side. The ambulatory ultrafiltration also includes a buffer vessel in fluid communication with the blood side of the blood filter, and a blood pump. The blood pump is controlled to alternate between a withdrawal phase and a return phase. In the withdrawal phase, blood is withdrawn on a blood path from the subject via the blood filter to the buffer vessel. In the return phase, blood is returned from the buffer vessel to the subject on the blood path. The blood filter is arranged to remove ultrafiltrate from the blood during at least one of the withdrawal and return phases.

主权项

1. An ambulatory ultrafiltration device for connection to the vascular system of a subject, comprising:
a blood filter having a blood side configured for fluid communication with the vascular system of the subject, an ultrafiltrate side configured for fluid communication with a receptacle for receiving ultrafiltrate, and a semipermeable membrane disposed between the blood side and the ultrafiltrate side; a blood pump including a membrane chamber which defines a blood side and a drive fluid side separated by a flexible membrane, the blood side of the membrane chamber connected in fluid communication with the blood side of the blood filter, the blood pump operable to alternate between a withdrawal phase and a return phase, wherein the withdrawal phase comprises blood being withdrawn along a blood path in fluid communication with the subject and the blood filter to the blood side of the membrane chamber, and the return phase comprises blood being returned from the blood side of the membrane chamber to the subject on said blood path; a drive fluid pump in fluid communication with the drive fluid side of the membrane chamber and the receptacle, the drive fluid pump operable to pump liquid from the receptacle out of and into the drive fluid side of the membrane chamber during the withdrawal and return phases; and a control unit programmed to cause the blood filter to perform ultrafiltration, such that the blood filter separates ultrafiltrate from plasma in the blood without changing a plasma concentration of small solutes in the blood, during at least one of the withdrawal and return phases.