Artificial KidneyArtificial Kidney• Dialyzing membrane has small holes.Dialyzing membrane has small holes.• Average diameter of holes is 50 Å (1 Å = 10Average diameter of holes is 50 Å (1 Å = 10-10-10 m). m).• Waste products in blood are able to pass through Waste products in blood are able to pass through

these holes into dialysate fluid. these holes into dialysate fluid. DiffusionDiffusion• Due to concentration gradient across membrane, Due to concentration gradient across membrane,

waste product will pass through.waste product will pass through.• Dialysate fluid free from waste product Dialysate fluid free from waste product

molecules.molecules.• Thus, waste products in blood tend to distribute Thus, waste products in blood tend to distribute

evenly throughout blood and dialysate.evenly throughout blood and dialysate.• Movement of waste products from blood to Movement of waste products from blood to

dialysate results in cleaning of the blood.dialysate results in cleaning of the blood.

Artificial KidneyArtificial KidneyConvectionConvection• Volume of body fluid cannot be controlled by Volume of body fluid cannot be controlled by

dialysis.dialysis.• Ultra-filtration across membrane is employed. Ultra-filtration across membrane is employed. • Positive pressure applied to blood compartment.Positive pressure applied to blood compartment.• Or negative pressure established in dialysate Or negative pressure established in dialysate

compartment.compartment.• Thus, fluid (water and electrolytes) will move Thus, fluid (water and electrolytes) will move

from blood compartment to dialysate.from blood compartment to dialysate.• Degree of ultra-filtration depends on pressure Degree of ultra-filtration depends on pressure

difference across membrane and ultra-filtration difference across membrane and ultra-filtration characteristic of membrane.characteristic of membrane.

Artificial KidneyArtificial KidneyComparison with Natural KidneyComparison with Natural Kidney• Artificial kidney is a membrane separation Artificial kidney is a membrane separation

device that serves as mass exchanger device that serves as mass exchanger during clinical use. during clinical use.

• It is unable to perform any metabolic It is unable to perform any metabolic functions of normal kidney.functions of normal kidney.

• Therefore, it cannot correct abnormalities Therefore, it cannot correct abnormalities results from the loss of kidney function. results from the loss of kidney function.

• Artificial kidney can only substitute kidney Artificial kidney can only substitute kidney in the transfer of unneeded substances in the transfer of unneeded substances from blood to be eliminated from the body.from blood to be eliminated from the body.

DialyzersDialyzers• The part in artificial kidney system where The part in artificial kidney system where

blood is freed from waste products.blood is freed from waste products.Components of DialyzerComponents of Dialyzer• Blood compartment.Blood compartment.• Dialysate compartment. Dialysate compartment. • Semipermeable membrane.Semipermeable membrane.• Membrane support structure.Membrane support structure.Design Consideration of DialyzerDesign Consideration of Dialyzer• Can be classified according to three basic Can be classified according to three basic

design considerations : parallel plate, coil design considerations : parallel plate, coil and hollow fiber.and hollow fiber.

• Clearance of substances from blood depends Clearance of substances from blood depends upon the rate of blood flow. upon the rate of blood flow.

DialyzersDialyzers• Rate and pattern of dialysate flow could also Rate and pattern of dialysate flow could also

influence overall performance.influence overall performance.• Since dialysis is based on concentration Since dialysis is based on concentration

gradient, it is desirable to maintain zero gradient, it is desirable to maintain zero concentration of waste substances in concentration of waste substances in dialysate.dialysate.

• This could be done by using dialysate only This could be done by using dialysate only once.once.

• Resistance to blood flow in dialyzer should be as low Resistance to blood flow in dialyzer should be as low as possible.as possible.

• The purpose having low resistance is to eliminate The purpose having low resistance is to eliminate the need for blood pump.the need for blood pump.

• All the blood that flow through the blood All the blood that flow through the blood compartment of dialyzer should be completely compartment of dialyzer should be completely returned to patient.returned to patient.

DialyzersDialyzersParallel Flow DialyzerParallel Flow Dialyzer• Use parallel plates with ridges and grooves in Use parallel plates with ridges and grooves in

them.them.• Low internal resistance, allows adequate blood Low internal resistance, allows adequate blood

flow through dialyzer.flow through dialyzer.• Rigid supports permit negative pressure to be Rigid supports permit negative pressure to be

created on dialysate side for ultra-filtration.created on dialysate side for ultra-filtration.KIIL Dialyzer KIIL Dialyzer • An example of this kind of dialyzer is KIIL An example of this kind of dialyzer is KIIL

Dialyzer.Dialyzer.• Consists of three polypropylene boards with Consists of three polypropylene boards with

dialyzing membranes laid between them.dialyzing membranes laid between them.• Rubber gasket runs along the periphery of the Rubber gasket runs along the periphery of the

boards inner surface to prevent blood and boards inner surface to prevent blood and dialysate leakage. dialysate leakage.

DialyzersDialyzers

DialyzersDialyzers• Dialysate enters through a stainless steel port.Dialysate enters through a stainless steel port.• It is then distributed to grooves running across It is then distributed to grooves running across

the end of the board above and below membrane the end of the board above and below membrane of each layer.of each layer.

• It flows down longitudinal grooves in the boards It flows down longitudinal grooves in the boards before collected and flow out at opposite end of before collected and flow out at opposite end of the board.the board.

• Dialyzer not disposable but need to be cleaned Dialyzer not disposable but need to be cleaned after each dialysis operation.after each dialysis operation.

Coil DialyzerCoil Dialyzer• Tubular membrane placed between flexible Tubular membrane placed between flexible

support wrapped around a rigid cylindrical core.support wrapped around a rigid cylindrical core.• The coil is immersed in a dialyzing bath.The coil is immersed in a dialyzing bath.

DialyzersDialyzers

DialyzersDialyzers• The design of coil dialyzer is simple.The design of coil dialyzer is simple.• However it has performance limitations which However it has performance limitations which

restricted its use better design evolved.restricted its use better design evolved.• Coil design did not produce uniform dialysate Coil design did not produce uniform dialysate

flow distribution across membrane.flow distribution across membrane.• High resistance to blood.High resistance to blood.

Hollow Fibre DialyzerHollow Fibre Dialyzer• Most commonly used.Most commonly used.• Consists of thousands of hollow de-acetylated Consists of thousands of hollow de-acetylated

cellulose diacetate capillaries.cellulose diacetate capillaries.• The capillaries are jacketed in a plastic The capillaries are jacketed in a plastic

cylinder.cylinder.

DialyzersDialyzers

DialyzersDialyzers• The capillaries range from 200-300 mm The capillaries range from 200-300 mm

internal diameter and wall thickness of 25-30 internal diameter and wall thickness of 25-30 um.um.

• Dialyzing area approximately 9000 cmDialyzing area approximately 9000 cm22/unit./unit.• The blood introduced and removed through The blood introduced and removed through

manifold headers.manifold headers.• The dialysate is drawn through the jacket The dialysate is drawn through the jacket

under negative pressure outside of the under negative pressure outside of the capillaries.capillaries.

• Dialyzers are disposable.Dialyzers are disposable.• Advanteges of disposable dialyzers :Advanteges of disposable dialyzers :• - reduction in infection risk.- reduction in infection risk.• - reduce operator set-up time.- reduce operator set-up time.• - eliminate dialyzer sterilization procedure.- eliminate dialyzer sterilization procedure.

Peritoneal DialysisPeritoneal Dialysis• Peritoneum acts as a filter/semipermeable Peritoneum acts as a filter/semipermeable

membrane. membrane. • Peritoneum is a membrane that lines the abdomen and Peritoneum is a membrane that lines the abdomen and

covers the abdominal organscovers the abdominal organs..• A sterile solution containing minerals and A sterile solution containing minerals and

glucose is run through a tube into the peritoneal glucose is run through a tube into the peritoneal cavity.cavity.

• Peritoneum membrane has a large surface area Peritoneum membrane has a large surface area and a rich network of blood vessels. Substances and a rich network of blood vessels. Substances from the blood can easily pass through the from the blood can easily pass through the peritoneum into the abdominal cavity .peritoneum into the abdominal cavity .

• The dialysate is left there for a period of time to The dialysate is left there for a period of time to absorb waste products, and then it is drained out absorb waste products, and then it is drained out through the tube and discarded. through the tube and discarded.

Peritoneal DialysisPeritoneal Dialysis

HemodialysisHemodialysis• Blood is removed from the body and pumped by a Blood is removed from the body and pumped by a

machine outside the body into a dialyzer . machine outside the body into a dialyzer . • Dialyzer filters metabolic waste products from the Dialyzer filters metabolic waste products from the

blood and then returns the purified blood to the blood and then returns the purified blood to the person .person .

• Ultrafiltration occurs by increasing the hydrostatic Ultrafiltration occurs by increasing the hydrostatic pressure across the dialyzer membrane, usually pressure across the dialyzer membrane, usually done by applying a negative pressure to the done by applying a negative pressure to the dialysate compartment of the dialyzer. dialysate compartment of the dialyzer.

• Can be an outpatient or inpatient therapy Can be an outpatient or inpatient therapy conducted in dialysis centre or hospitals and conducted in dialysis centre or hospitals and clinics which have the facilities.clinics which have the facilities.

• Patients must undergo strict schedule of Patients must undergo strict schedule of treatment usually three times a week for 3 to 5 or treatment usually three times a week for 3 to 5 or more hours each visit. . more hours each visit. .

HemodialysisHemodialysis• Yayasan Buah Pinggang Kebangsaan Yayasan Buah Pinggang Kebangsaan

Malaysia – involve in providing facilities for Malaysia – involve in providing facilities for kidney treatment and education for people. kidney treatment and education for people. (www.nkf.org.my)(www.nkf.org.my)

• Pusat Dialisis Tuanku Syed Putra (NKF)Pusat Dialisis Tuanku Syed Putra (NKF)

Yayasan Amal Tuanku Hajah Budriah Perlis, Yayasan Amal Tuanku Hajah Budriah Perlis,

Lorong Hilary, Taman Bukit Kaya, Lorong Hilary, Taman Bukit Kaya,

Jalan Bukit Lagi, Jalan Bukit Lagi,

Kangar, 01000 Perlis.Kangar, 01000 Perlis.

04-977741104-9777411

Hemodialysis MachineHemodialysis Machine• Hemodialysis machine is used for production of warm Hemodialysis machine is used for production of warm

dialysate which is then circulated through an external dialysate which is then circulated through an external dialyzer assembly. dialyzer assembly.

• Also controls cycling of blood from patient to dialyzer Also controls cycling of blood from patient to dialyzer and back to the patient.and back to the patient.

• Continuously controls and monitors all important Continuously controls and monitors all important parameters. parameters.

• Automatically halts treatment if there is abnormality Automatically halts treatment if there is abnormality or in the event of parameters going out of preset limit.or in the event of parameters going out of preset limit.

• Pumps and controls flow of blood at pre-determined Pumps and controls flow of blood at pre-determined rate and pressure to ensure effective clearances and rate and pressure to ensure effective clearances and fluid removal.fluid removal.

• Also measures ultra-filtration rate.Also measures ultra-filtration rate.• With all parameters known, operator could calculate, With all parameters known, operator could calculate,

predict and control fluid removal during dialysis. predict and control fluid removal during dialysis.

Hemodialysis MachineHemodialysis Machine

Hemodialysis MachineHemodialysis Machine

Hemodialysis MachineHemodialysis Machine

Hemodialysis MachineHemodialysis Machine

Hemodialysis MachineHemodialysis Machine

Hemodialysis MachineHemodialysis Machine