TOPIC:- HEMODIALYSIS MACHINE

Presented by:-

Gohel nita g.(120133103022)

Vaghasiya nayana r.(120133103025)

Zankat hiral b.(120133103026)

Gamit vilesh v.(120133103029)

Guided by:-

Nilam modi

INTRODUCTION

In medicine, hemodialysis (also haemodialysis) is a method that is used to achieve the extracorporeal removal of waste products such as creatinine and urea and free water from the blood when the kidneys are in a state of renal failure.

Hemodialysis is one of three renal replacement therapies (the other two being renal transplant and peritoneal dialysis).

An alternative method for extracorporeal separation of blood components such as plasma or cells is apheresis.

Hemodialysis can be an outpatient or inpatient therapy. Routine hemodialysis is conducted in a dialysis outpatient facility, either a

purpose built room in a hospital or a dedicated, stand alone clinic. Less frequently hemodialysis is done at home. Dialysis treatments in a clinic are initiated and managed by specialized staff

made up of nurses and technicians; dialysis treatments at home can be self initiated and managed or done jointly with the assistance of a trained helper who is usually a family member.

PRINCIPLE

The principle of hemodialysis is the same as other methods of dialysis; it involves diffusion of solutes across a semipermeable membrane. Hemodialysis utilizes counter current flow, where the dialysate is flowing in the opposite direction to blood flow in the extracorporeal circuit. Counter-current flow maintains the concentration gradient across the membrane at a maximum and increases the efficiency of the dialysis.A hemodialysis machine is used for the production of warm dialysate which is then circulated through an external dialyzer assembly.It also controls the cycling of the blood from the patient through the artificial kindey and back to the patient .It continuously monitors and going out of pre-set limit. The hemodialysis machine performs five basic function:-

1) Mixes the dialysate2) Monitors the dialysate3) Pump the blood and control administration of anticoagulate 4) Monitors the blood for the presence of air and drip chamber pressure and5) Monitors the ultra- filteration rate.

APPLICATION

Hemodialysis machine treatments replace some kidney functions by removing waste and fluid from the bloodstream via diffusion and osmosis of solutes and fluid across a semipermeable dialysis membrane.

Blood in one compartment is pumped along one side of the membrane while a dialysate (a crystalloid solution that acts as a sponge for impurities) is pumped along the other side, in a separate compartment, in the opposite direction.

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

This pressure gradient causes water and dissolved solutes to move from the blood to the dialysate.

The cleansed blood returns via the circuit back to the body. Honeywell manufactures many sensors that may be used in hemodialysis

machines. They provide presence/absence detection, pressure/flow and temperature

measurement.

WORKING

The hemodialysis machine pumps the patient's blood and the dialysate through the dialyzer. The newest dialysis machines on the market are highly computerized and continuously monitor an array of safety-critical parameters, including blood and dialysate flow rates; dialysis solution conductivity, temperature, and pH; and analysis of the dialysate for evidence of blood leakage or presence of air. Any reading that is out of normal range triggers an audible alarm to alert the patient-care technician who is monitoring the patient.

MAIN PARTS:-1) water system2) dialyzer

Water system

An extensive water purification system is absolutely critical for hemodialysis. Since dialysis patients are exposed to vast quantities of water, which is mixed with dialysate concentrate to form the dialysate, even trace mineral contaminants or bacterial endotoxins can filter into the patient's blood. Because the damaged kidneys cannot perform their intended function of removing impurities, ions introduced into the bloodstream via water can build up to hazardous levels, causing numerous symptoms or death. Aluminum, chloramine, fluoride, copper, and zinc, as well as bacterial fragments and endotoxins, have all caused problems in this regard.

For this reason, water used in hemodialysis is carefully purified before use. Initially it is filtered and temperature-adjusted and its pH is corrected by adding an acid or base. Then it is softened. Next the water is run through a tank containing activated charcoal to adsorb organic contaminants. Primary purification is then done by forcing water through a membrane with very tiny pores, a so-called reverse osmosis membrane. This lets the water pass, but holds back even very small solutes such as electrolytes. Final removal of leftover electrolytes is done by passing the water through a tank with ion-exchange resins, which remove any leftover anions or cations and replace them with hydroxyl and hydrogen molecules, respectively, leaving ultrapure water.

Once purified water is mixed with dialysate concentrate, its conductivity increases, since water that contains charged ions conducts electricity. During dialysis, the conductivity of dialysis solution is continuously monitored to ensure that the water and dialysate concentrate are being mixed in the proper proportions. Both excessively concentrated dialysis solution and excessively dilute solution can cause severe clinical problems.

Dialyzer

The dialyzer is the piece of equipment that actually filters the blood. Almost all dialyzers in use today are of the hollow-fiber variety. A cylindrical bundle of hollow fibers, whose walls are composed of semi-permeable membrane, is anchored at each end into potting compound (a sort of glue). This assembly is then put into a clear plastic cylindrical shell with four

openings. One opening or blood port at each end of the cylinder communicates with each end of the bundle of hollow fibers. This forms the "blood compartment" of the dialyzer. Two other ports are cut into the side of the cylinder. These communicate with the space around the hollow fibers, the "dialysate compartment." Blood is pumped via the blood ports through this bundle of very thin capillary-like tubes, and the dialysate is pumped through the space surrounding the fibers. Pressure gradients are applied when necessary to move fluid from the blood to the dialysate compartment.

Advantages

Low mortality rate Better control of blood pressure and abdominal cramps Less diet restriction Better solute clearance effect for the daily hemodialysis: better tolerance and

fewer complications with more frequent dialysis.

Disadvantages

Restricts independence, as people undergoing this procedure cannot travel around because of supplies' availability

Requires more supplies such as high water quality and electricity Requires reliable technology like dialysis machines The procedure is complicated and requires that care givers have more

knowledge Requires time to set up and clean dialysis machines, and expense with

machines and associated staff.

Technical Specifications for Dialysis Machine

Should have facility for conventional and High flux dialysis. Machine should have two bacterial filter (Pyrogen filters) one at water inlet and one before water going to dialyser.Battery back-up for 20-30 minutes to run complete machine with heater supply Dialysate temperatures selectable between 35 degrees C to 39 deg. C Variable conductivity setting between 12 to 15 Should have variable dialysate flow 200-800 ml/mt and should have increasing facilty to step up by 2o ml. Should have facility to show trends curve of all parameter for 15-20 minutes.Heparin pump with syringe sizes 20 to 30 ml with pump flow rate from 1-10 ml/hr ( 0.1 ml increments) Stroke pressure operated short term single needle dialysis Ultrafiltration 0.1 to 2.5 litres/hr. The in and out fluid circuit must be separated so that there is no chance of contamination in the event of membrane rupture. Treatment parameter should be displayed by graph and digitally both Should have integrated heat and chemical disinfection facility with one standard time. disinfection programme with day knight week schedule Should have accurate feedback control conductivity mixing technique. Should have drain facility. Should have accurate UF control by flow by volume control measurement technique. Extra facilities like Blood Volume sensor,Bicart Select technique and online clearance kt/V and blood temperature monitor. All important data should be presetted so that machine can be used anytime without feeding data every time .Should have automatic self test facility. Should have auto ON/OFF Facility .Machine can be connected to computer to feed all data and trouble shoot whenever any problem .Blood pump rate from 20-500 ml/min adaptable to stndard A-V bloodliness 140.Audio visual alarms on limit violation of conductivity,blood leak, air leak, transmembrane pressure alarms. Dialysis temperature alarm,dialysis can empty alarm, end of disinfection alarm,bypass alarm and blood pump stop alarm. Alarm for reverse Ultra filtration and also be able to do sequential dialysis.