Indian J Pediat 50 : 259--262 1983

Indigenous automatic peritoneal dialysis unit V.P. Choudhry, M.D., B. Bhattacharya, Ph.D., S.M.K. Rehman, Ph.D.,

and S.N. Tandon, Ph.D.

Automatic peritoneal dialysis unit has been developed and fabricated indigenously From multiple electronic a n d electro-magnetic com- ponents available in India. Flow of f luid in and out o f the periton- eal cavity is controlled automatically. Dialysis f lu id o f each cycle is weighed mechanically. I t ' f low o f f lu id is inadequate the unit gives both audio and visual alarm for immediate attention. Number o f cycles and total return o f the f luid can be observed at an)' time. Risk o f infection has been minimised as there is no need to ~ hange the dialysis f luid at each cycle. There is no need to autoclave the unit as the dialysis f luid does not come in direct contact with the unit. Bunning cost of the unit is onO' the cost of dialysis fluid. With easy availability o f this unit the peritoneal dialysis facilities can be made available in each hospital and even at home in children with chronic ronal failure. This will improve the health care o f children with renal failure. The approximate cost o f the unit will be Rs. 10,000 onO'.

Key words: Automatic peritoneal dialysis unit; electronic; electromagnetic components.

indigenous;

Acute renal failure (ARF) is an im- portant problem in the hospital practice and accounts for 1-1.5 percent of hospital admission. 1'2 Majority of children with ARF recover completely provided cum- mulative metabolitis are removed by peritoneal or hemodialysis during the acute stage, In our experience nearly half of our childern with ARF needed peritoneal dialysis. 1 Peritoneal dialysis is generally preferred in children because of technical case and in adults where hemodialysis facilities are not available) This is a simple and safe procedure but

Departments of Pediatrics and Biomedical Engineering Division, All India Institute of Medical Sciences and Indian Institute of Technology, New Delhi Repri*~t requests : Dr V.P Choudhry, Assistant Professor. Department of Pediatrics

needs a constant supervison of trained personnel for a period of 40--48 hours. An indigenous automatic unit for peri- toneal dialysis has been developed and fabricated which is being described in this paper.

Present method of peritoneal dialysis

Procedure in use presently requires physical presence of trained staff to monitor inflow and outflow of dialysis fluid for 40--48 hours. Dialysis fluid enters the peritoneal cavity by gravita- tional force and is drainedout by siphon mechanism. Dialysis procedure currently in practice has been described earlier)

Development and fabrication of dialysis unit

The inflow and outflow of dialysis

260 THE INDIAN JOURNAL OF PEDIA'I-RICS

fluid from the peritoneal cavity is con- trolled by two electromagnetic valves (EMVz EMV.,). These valves control the flow of fluid from outside. Electro- magnetic EMV1, opens for desirable time to facilitate flow of dialysis fluid into the peritoneal cavity by gravity. EMV,. opens after desirable length of time, so that fluid from peritoneal cavity can be siphoned out into weighing bag (Fig. 1). Volume of fluid, drained out in each cycle is weighed on the weighing scale. Automatic audio and visual alarm system had been incorporated to monitor the volume of fluid drained out in ecch cycle. Alarm is pro- duced if the contact as shown in Fig. 2 does not break and this condition will arise whenever the fluid drained is less than the desired volume. With the ade- quate fluid drained out, next cycle starts automatically and simultaneously electromagnetic EMVa opens to allow fluid to drain out to the large waste container. This electromagnetic system (EMV3) opens during phase I and 1I of each cycle.

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Fig. I - Dialysis system showing the placing of electromagnetic valves, weighing bag and waste container.

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Opening and closing of various electromagnetic valves is controlled by an automatic electronic time and sequ- ence controlling system (Eig 3). This system is composed of three timers which in turn controlles the three phases of a cycle. Phase I is for inflow of dialysis fluid into peritonium and is con- trolled by timer I. Dialysis fluid rema- ins in the peritoneal cavity during phase II which is controlled by timer II. Timer III controles Phase III in which electro- magnetic EMV3 opens permitting the flow of fluid from drainage bag to the major waste container.

Unit starts functioning whcn reset switch and trigger switch are pressed in sequence. Dialysis cycle starts with opening of electromagnetic EMV1. Completion of each cycle is recorded on the digital display fitted in the electronic time sequence controlling system. In case of light failure or poor drainage from the peritoneal cavity, another trigger Tr2 is fitted to restart the cycle from phage III (i.e. outflow phases).

Application of peritoneal dialysis unit

After fabrication of laboratory model the unit was tested in the laboratory under simulating condition to test the reliability of electronic time sequence controlling system, leakage in the electromagnetic valves and alarm system. After its successful performance the unit was tested twice on guinea pig and twice on rabbit for variable period of time and in different time sequences. In all these experimental the dialysis unit performance was satisfactory and faul- tless. After its initial success on the experimetal animal, this unit has been used in 10 children with A.R.F. No problems were encountered during the dialysis procedure on these children.

c H O U D H R Y E T A L : P E R I T O N E A L D I A L Y S I S U N I T 261

, N I : O R M A ] I O N OF

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Discussion

Present automatic peritoneal dialysis system has been developed to relieve the physicians and attending staff from the repeated and time consuming procedure. One of the advantage is that the dialysis

fluid does not come in direct contact with dialysis unit as inflow and outflow is being controlled with the help of the electromagnetic valves (EMVz, EMV~ and EMV3). In the unit under trial 8 dialysis fluid bottles are used at a time. The risk of infection to patient is less as bottles

262 TIlE INDIAN JOURNAL oF PEDIATRICS

are being changed less frequently. Visual and auditory alarm included in the system for predetermined amount of drained fluid avoids the overloading I of the peritoneal cavity. In case of an alarm, cycle from phase 1II can be start- ed by the physician after ensuring that there is no block in the fluid circuit. Fluid from the weighing system is be- ing drained during phase I and 1I to the waste container to ensure the complete emptying of the weighing system. Total out-flow can be recorded at any time from the waste container which is also graduated.

Inflow volume can be controlled by changing the force of gravity and time period of phase I. All the three phases have wide range of variability from 1-99 minutes.

This laboratory model of the dialysis unit has given satisfactory performance in simulating conditions in the labora- tory on experimental animals and in children with ARF. This unit is easy to

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operate and does not need any prior training. Running cost of unit is only the cost of dialysis fluid as unit runs on electricity and does not need any special preparation, It is an automat ic system and does not disturb the patient. Further development and easy availability of the unit will encourage its use for patients at home in cases with chronic renal failure.

References

1. Choudhry VP, Srivastava RN, Vellodi A, Bhuyan UN, Ghai OP, A study of acute renal failure, htdian Pediatr 17 : 405, 1980

2. Raghupathy P, Date A, Shastry JCM, Jadhav M, Pereira SM, Acute Renal failure in childhood. Ten year's experience. Proceedings XVII National Conference of the Indian Academy of Pediatrics. Bangalorr I980, p 104

3. Srivastava RN, Choudhary VP, Mayekar G, Anand R, Patra P, Ghai OP, Peritoneal dialysis I Experience in 28 eases. Indian Pediatr 12 : 487, 1975