Control Systems in Medical Applications AS ICT Control Systems in Medical Applications

Objectives Have an understanding of how organizations use ICT. Be able to describe a number of uses, giving the hardware and software requirements Be able to describe the applications that these uses can be put to.

The main use of computer control in hospitals is in life-support systems. Sensors attached to a patient monitor  pulse temperature blood pressure breathing rate The readings are taken at regular intervals and used as input to a computer.If any of these readings goes outside acceptable levels an output signal sets off an alarm to alert the nursing staff.  

These systems may be used for patients in intensive care (eg after operations) prematurely born babies The advantages of this system: monitoring can be continuously done 24 hours a day no chance of human errors due to eg tiredness frees the nursing staff to carry out other duties Disadvantages: these systems are expensive

Why use microprocessors in medical applications? Greater accuracy than a human Lower running costs compared with a human 24/7 monitoring of patients (robots do not get tired) Monitoring of many different systems at once Very rapid response Continuous process, no need for breaks Can monitor several patients at once – nurses are freed up to do other things

Medical applications Computer control used in two major medical applications: Intensive care Surgery However, both still require human intervention, so we regard it as an open loop system

What is an open loop system? The output does not automatically directly affect the input Instead, the output is usually some sort of a signal (an alarm/flashing light etc) which alerts humans to the need for intervention

Open loop systems Monitoring & Measurement rather than control

Closed loop systems In a closed-loop control system, a sensor monitors the output (the vehicle's speed) It feeds the data to a computer which continuously adjusts the control input (the throttle) as necessary to keep the control error to a minimum (that is, to maintain the desired speed).

Intensive care: Patients monitored with sensors Blood pressure Pulse rate Body temperature Computer is pre-set with normal range of values Constantly compares data sent back by the sensors to those values If any body-function data falls outside the pre-set values, an alarm sounds

Surgery Robotic surgery using robotic arms & cameras inside the patient’s body End effector: usually a scalpel Surgeon controls robotic arms by using a console When the surgeon moves her/his hands, the robot arms & cameras respond exactly to the moves they make Surgeon is in complete control, but the work is more accurate Less invasive Smaller scale surgery Quicker recovery time Less occupation of hospital beds

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