Dialysis-on-the-go

Dialysis-on-the-go

Radio Singapore International.
May 29, 2007

Do you know where your kidneys are? And what function do they perform in our everyday life? People who suffer from renal failure are unfortunately only too aware of the importance of these two 150 grams bean shaped organs.

This week, Frontiers explores the potential of a new device that promises to bring new life to those who are suffering from kidney failure. Welcome to the programme with me, Loretta Foo.

Renal failure happens when the kidneys are unable to fulfill their normal function of filtering waste from the blood. This means that the person’s body has no way of getting rid of the waste which usually mixes with water and comes out as urine. Patients have to go on dialysis which is an artificial replacement for their kidneys.

A multi-disciplinary team from Temasek Polytechnic is currently working on an Automated Wearable Artificial Kidney or AWAK. Its creation requires a wide range of expertise in mechanical design, biomedical engineering and clinical study among other fields.

Tan Kim Cheng is the project leader for the venture. He explains that it was the painful plight of kidney patients that spurred the team to come up with this revolutionary product.

TKC: Previously, if the patient opted for the hemo-dialysis, they would have to go down to the dialysis centre regularly – at least two time a week – and it can be very expensive. Once, we visited a particular dialysis centre, and they told us it can be about $2000 a month, and these patients are only earning about $1000+ a month, so to maintain this treatment is a very costly affair. It is also very time-consuming and is a drawn-out affair on the part of the patient. They have to sit there for a few hours to have his or her blood cleansed.

Now, this device is known as a wearable kidney that is dialysis-on-the-go basically. How easy is it for patients to actually make use of this wearable kidney?

TKC: Just to give you an idea, (it is) something like a vest and the device is distributed around the vest. You just need to put on that vest, and maybe you can then have another shirt or coat over it. The neat thing about this is that (it) gives you the freedom to move around while the treatment is still ongoing.

How durable is this device? Will it allow someone for example to engage in fairly vigorous activity while wearing it?

TKC: We would put it this way – (it will allow a) limited active lifestyle because we would have incorporated into the design the various activities of a patient. We are designing it for young children to working adults right up to the elderly. As per daily living, it should not be a problem – meaning (for example) going to school, going up and down a bus, walking at home. We have not ventured at this point in time to say that yes, you can take this around and be actively engaged in a badminton tournament. Not at this point in time.

What other benefits are there to this kidney machine other than the fact that it is actually mobile?

TKC: It (is a) continual process cycle in which the blood is being cleansed via the dialysis fluid in the peritoneal that flows at about 0.1 litre per minute. The dialysis fluid is regenerated, and therefore there is no need to replace the dialysis fluid. But also, more importantly, the cost of the cost of the treatment (is reduced) because the dialysis liquid is regenerated and you need not have to throw them (away) as what other systems would require.

You mentioned that anyone can do this themselves rather than to have a trained professional have to hook them up to the machine and all that? How difficult is it to maintain that?

TKC: There is this catheter that is embedded in your body. This catheter is connected to a tube in your peritoneal gland. What you need to do is to connect this catheter to the flow system and regularly you may need to remove the absorbent cartridge. This absorbent cartridge is what removes the waste product from the dialysis fluid.

I understand that your whole team is made up of many people, not just from engineering or the medical sciences department. What were some of the difficulties that you came across while fine-tuning this machine?

TKC: The key obstacle that we are facing presently is to miniaturise all those various components so that it can be facilitated into a wearable outfit, and also to distribute the various components in the outfit that is worn by the patient in a way that the weight is distributed uniformly, and it will not cause encumbrance in the movement of the patient.

That was Tan Kim Cheng, project leader of the AWAK.

Temasek Polytechnic is currently in consultation with the University of California at Los Angeles and local clinicians. They hope to release the AWAK on the market after medical trials are conducted.

Download podcasts of Frontiers to find out what’s happening on the cutting edge of science at www.rsi.sg/english.

I’m Loretta Foo signing off for Radio Singapore International.

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