US-12616938-B2 - Filter device for dialysis applications

Abstract

The current invention relates to a peritoneal dialysis filter device, which comprises a housing comprising a first port and a second port, and a hollow fibre membrane formed from hollow hydrophilic fibres within the housing. When in use, a dialysate from a subject enters the filter device through the first port and exits via the second port in an outflow direction, and a regenerated dialysate from a sorbent system enters the filter device through the second port and exits via the first port in an inflow direction. Also disclosed herein is a peritoneal dialysis system comprising said filter device, a method for controlling dialysate flow in a peritoneal dialysis system, and a haemodialysis device.

Inventors

• Jason Tze Chern LIM
• Peter Haywood
• Suresha BELUR VENKATARAYA
• Joel Preetham FERNANDES
• Daniel Wei Teik TAN
• Yue Wang
• Abel Samson DSOUZA
• Wenhui Dennis ONG
• Sanjay Kumar Singh

Assignees

• Awak Technologies Pte Ltd

Dates

Publication Date

20260505

Application Date

20210628

Priority Date

20200929

Claims (4)

1. 1 . A device for use in peritoneal dialysis consisting of: (i) a filter device; and (ii) a post-filtration system, wherein the filter device comprises: a housing comprising a first port and a second port; and a hollow fibre membrane formed from hollow hydrophilic fibres within the housing, where each of the fibres have an inner surface and an outer surface, wherein the hollow hydrophilic fibres comprise a porous wall matrix; and the inner surface of the hollow hydrophilic fibres are aligned co-axially with respect to the alignment of the first port and the outer surface of the hollow fibres is aligned perpendicularly with respect to the alignment of the second port, such that, when used: a dialysate from a subject enters the filter device through the first port is filtered through the porous wall matrix, and the filtered dialysate exits via the second port in an outflow direction; and a regenerated dialysate from a sorbent system enters the filter device through the second port, passes through the porous wall matrix, and exits via the first port in an inflow direction, and wherein the post-filtration system consists of: (a) a switch; (b) a post-filtration sorbent compartment; and (c) fluid connections connecting the post-filtration sorbent compartment, the switch and the first port of the housing, wherein the post-filtration system and filter device together form: a first fluid pathway consisting of the first port of the housing, the switch and a fluid connection therebetween; and a second fluid pathway consisting of the first port of the housing, the switch, the post-filtration sorbent compartment, and a fluid connection therebetween; where the switch is suitable for selecting between the first and second fluid pathways, where the first and second fluid pathways are both fluidly connected to the first port of the housing via the switch, where the post-filtration sorbent compartment comprises a post-filtration sorbent that is suitable for removing one or more of water-soluble uremic toxins, protein-bound uremic toxins, low-molecular weight proteins, endotoxins, exotoxins, inflammatory mediators and microorganisms.
2. 2 . The device according to claim 1 , wherein first fluid pathway is connectable to the subject's peritoneum via the switch; and the second fluid pathway is connectable to the subject's peritoneum via the post-filtration sorbent compartment.
3. 3 . The device of claim 1 , further comprising, a sorbent device, wherein the filter device is arranged to receive and filter the entirety of dialysate from the subject and to provide the filtered dialysate to the sorbent device when operated in an outflow direction; and the filter device is arranged to receive at least part of the regenerated dialysate from the sorbent device when operated in an inflow direction.
4. 4 . The device of claim 3 , wherein the device further comprises a bypass means or apparatus, which comprises: a bypass fluid pathway connected to the sorbent device and arranged to return a regenerated dialysate to the subject without passing through the filter device; and a switching means or apparatus that selects between sending a regenerated dialysate to the filter device or to the bypass fluid pathway.

Description

FIELD OF INVENTION The current invention relates to the field of a filter device for peritoneal dialysis and haemodialysis. Also disclosed herein are dialysis systems and methods that make use of said filters. BACKGROUND The listing or discussion of a prior-published document in this specification should not necessarily be taken as an acknowledgement that the document is part of the state of the art or is common general knowledge. Peritoneal dialysis (PD) is a type of dialysis which uses the peritoneum in a subject's abdomen as a membrane through which mass transfer of fluid and solutes occurs between dialysate and blood. This process is used to remove excess fluid, correct electrolyte and acid-base imbalances, and remove toxins in treatment of patients with kidney failure. In peritoneal dialysis, dialysate (a solution typically containing sodium chloride, sodium hydrogen carbonate/sodium lactate, and an osmotic agent) is introduced through a permanent tube in the lower abdomen, is allowed to dwell for a certain period of time and is then removed. This may either occur at regular intervals throughout the day, known as continuous ambulatory peritoneal dialysis (CAPD), or at night with the assistance of a machine, known as automated peritoneal dialysis (APD). Compared to haemodialysis, PD allows greater patient mobility, produces fewer swings in symptoms due to its continuous nature, and is inherently safer as it does not rely on extracorporeal circulation of the patient's blood. However, due to the oncotic pressure gradient in systems for peritoneal dialysis, proteins excreted by the subject are transported into the subject's peritoneum, where they mix together with toxins and electrolytes present in the dialysate fluid. There are multiple issues associated with this mixing. These include: (a) the fact that this mixing leads to significant protein loss from the subject over long-term peritoneal dialysis treatment; and(b) as proteins are relatively large in size, the proteins can get trapped inside the sorbent system (when such a system is used to remove toxins), thereby affecting sorbent efficiency. Additional problems that can be encountered with conventional PD systems include, but are not limited to the following. (1) In sorbent-based dialysis systems, such as the REDY system, CO2 produced during dialysate regeneration can become a health risk (hypercapnia) to patients with respiratory failure, and accumulated CO2 bubbles can compromise the effective surface area of the hollow fibres used in the REDY system, thereby diminishing their performance and dialysis efficiency. In sorbent dialysis, urea-laden dialysate flows through urease, where urea is hydrolysed to ammonium and bicarbonate. Zirconium phosphate adsorbs cations such as the ammonium ion, releasing sodium and hydrogen ions, with the hydrogen ions then reacting with bicarbonate to form CO2. In a closed-loop system without active degassing, such as the REDY system, this can lead to accumulation of potentially hazardous levels of pCO2 in dialysate and returned blood. While ordinary patients are apparently able to exhale excess CO2 with no adverse symptoms, patients with compromised respiratory systems were left in a hypercapnic, acidotic state. Therefore, conventional sorbent dialysis systems do not provide an effective CO2 removal mechanism and are dependent on the patients' breathing to compensate for the increased serum pCO2. Additionally, increased dialysate pCO2 can lead to spontaneous bubble formation, and the bubbles are prone to accumulate in the filter. Conventional filters in sorbent dialysis do not include a provision for bubble removal, hence the need for manual intervention to “burp the dialyzer” (the technical term used), and prevent loss of dialysis surface area and underdialysis. Besides routine kidney dialysis, CO2 removal is also a useful feature needed for dialysis in the acute care setting, for example in intensive care units (ICU). Current treatments use separate machines to deliver dialysis and for serum oxygenation/CO2 removal.(2) Protein-bound uremic toxins (PBUTs) have been implicated in numerous deleterious effects in chronic kidney disease (CKD) patients, as well as in end-stage renal disease (ESRD) patients. There is growing literature evidence suggesting that improving the dialytic removal of PBUTs can improve the outcomes for HD/PD patients. Methods have been proposed to remove PBUTs in both HD and PD systems. However, none of these methods have been proven on patients or integrated into existing devices. One of the main reasons why this has not occurred is that many of the solutions propose adding an albumin binder competitor into the dialysate solution, which alters the dialysate composition—and potentially alters the patient's serum composition. Therefore, these solutions are currently considered to be a drug and are therefore required to undergo rigorous clinical trials and regulatory processes before they can be app