INFUSION PUMP

GLOSSARY

Infusion:                                                

It is the application of a drug to a patient using the intravenous route, that is, the application of a drug directly in the bloodstream. 

Volume:                                                 
It refers to the amount of three-dimensional space occupied by a liquid, solid or gas.
Sensor:                                                  

Device that detects and responds to some type of input from the physical environment.

Pressure:                                               
Force exerting a gas, a liquid or a solid on a surface.
Time:                                                     

Period determined during which an action is performed or an event takes place.

DEVELOP 

The infusion pump is a medical device capable of supplying medication, through its programming and in a controlled manner by intravenous (para-enteral infusions) or oral (enteral infusions) to patients who, due to their condition, require it.

Characteristics:

• Precision

• Ability to modify the variable maximum pressure limit speed

• Variable maximum pressure limit:

• Good protection against free flow

• Detection and alarm of any incident

• Ability to detect extravasation

• Possibility of reducing the pressure before solving an occlusion

• Maximum occlusion pressure alarm limits

• Track maintenance flow

Advantages of using pumps:

·    They allow a greater accuracy in the drip rhythm than the gravity systems through a flow regulating clamp.

·      They save time for the nursing staff, since with the use of pumps it is not necessary to regulate the drip flow.

·  They allow all kinds of solutions to be administered, blood and its derivatives, drugs and parenteral and enteral infusions. Adaptable to the needs of the patient, some of them are portable.

·      Infusion pumps unlike gravity systems that are regulated by a trolley device that is adjusted by the nurse, if the patient changes position or if there is a contraposition or resistance to the system, modifies the flow of solution creating errors of administration. There is a higher incidence of phlebitis, fluid overload, etc.

TYPES OF INFUSION PUMPS 

Linear peristaltic pumps: This type of pumps has undergone several modifications in its design that guarantee today levels of precision close to those of positive displacement. Current peristaltic linear pumps have pressure limitations and offer precise volumes of liquid delivery. Its operation is the use of a certain number of "fingers" that "milk" the liquid and makes it descend through a straight channel for its infusion in the patient.

 Figure 1. Linear peristaltic pumps

Figure 2. Peristaltic pump- Lineal system

Rotating peristaltic pumps: They are the most used using a rotor that pushes the rollers against a tube along a semicircular trajectory. Separation of plasma cells.

 Figure 3. Rotating peristaltic pumps

Figure 4. Rotary System

Syringe Pumps: Stanes have a motor (a gear reducer mechanism and a lead screw) that apply force to the plunger of a syringe containing the medication. The device is mainly suitable for applications that require the delivery of volumes limited by the size of the syringe.

Figure 5. Syringe pump

Figure 6. Principle of syringe pump

Implantable infusion pumps: The pump stores and releases prescribed amounts of medication. It is contained in a round metal casing approximately one inch thick and three inches in diameter; It weighs about six ounces. The main components are a miniature peristaltic pump, drug reservoir, battery, antenna and microprocessor. The pump is surgically implanted, usually in or near the abdomen.

Figure 5. Implantable infusion pumps

Figure 5. Parts implantable infusion pump 

Some recommendations:         

·  In a battery-operated pump, these should be replaced on a regular basis to avoid jeopardizing the safety of patients in the event of a sudden stop.

·   Pumps that do not have an integrated function of protection against free flow should be clearly identified and complemented by a training program on their management offered to users.

·   Pumps often have sudden deceleration or fall to the ground, so they must be inspected mechanically as part of a control and safety process.

RESULTS

   The block diagram shown in the upper part represents the infusion pump emulator equipment made, the quantity of doses and the delivery time were controlled from a keyboard, the optical sensors fulfilled the task of detecting bubbles, occlusion and lack of medication in the system and emit a visual and auditory alamar in case of any circuit failure, the above was transmitted to the microprocessor which controlled the peristaltic pump and finally all parameters could be displayed in the corresponding display, for the source was worked at 12V the power supply of the motor, for adjustments of the screen a voltage regulator was used to obtain only 5V as well as for the use of the sensors.

Figure 6. Block diagram of infusion pump emulador equitmet

   The schematic diagram made in proteus® allows to observe a large part of the components used in the development of the guide, the arduino® mega microcontroller allowed the appropriate development in front of the number of pins requested for the connection of the graphic display, the keyboard, the motor which was anchored to a structure to form the peristaltic pump, the optical sensors configured in such a way as to allow reading and handling of analogous data for their respective characterization in the program.

Figure 7. Schematic diagram of infusion pump emulador equitmet

  The final product is shown in the lower images, there was a container for the control module of the system, in which the keyboard can be seen on one side and the display on the front, the system had an internal audible alarm and with 4 visual indicators, leds in this case, which corresponded to the blue for on / off system, the green for the detection of bubbles in the system, the yellow for occlusion system in fault and finally the red to indicate lack of medicine in the container taken as syringes.

  The peristaltic pump is placed in a frame in high state and able exert force for operation across systems clamp, the system had two syringes appropriately marked to indicate the initial amount of medication and the end portion thereof.

Figure 8. Front view of infusion pump proposed

Figure 8. Side view of infusion pump proposed

   In the video you can see how the circuit works, for example the passage of medication (for this case water), which circulated at a certain speed from the input parameters, the system consists of a macro-drip which also it is evidenced in the taking and as a characteristic part the detection of bubbles and its audible and visible alarm (the LED on and off), for this case the obstruction alarm is not appreciated because the circuit is without interference nor the lack of medication alarm because there was enough in the containers for optimal operation.

CONCLUSIONS

   With the work done is concluded for the operation of the infusion pump (rotary peristaltic infusion pump) it is essential to obtain the proper occlusion of the hose (in this case a pump) to prevent fluid from circulating when the equipment is turned off. Also; a good connection between hoses must be taken into account to avoid leaks in the system and variations in the quantity of medicine delivered.