Key Factors to Consider when Designing Biomedical Instruments

Some of the important factors that are considered when designing a medical measuring instrument include:

1. Patient safety considerations –Since medical instruments have to be physically connected to the patient, there is the possibility of an electric shock hazard in cases where there is electric or electronic equipment unless adequate measures have been taken in the design of the medical equipment to prevent such kind of hazards. All safety measures need to be ensured during the operation of the medical instrument.
2. Transducer interface problems –All instrumentation systems are affected in some way by the presence of the measuring transducer. This problem may get compounded while making measurement on the living system where the physical presence of the transducer may change the reading significantly. Besides, the presence of a transducer in one system can affect response in other system. Therefore, adequate care needs to be taken while designing a medical measuring system to ensure that the loading effect of the transducer is minimal on the source of the measured variable.
3. Measurement range –Generally, physiological signals measurement ranges are quite low to other parameters outside the medical field. The biomedical signals are usually very small in the microvolt range. Therefore, it is important to consider this when designing any medical instrument.
4. Frequency range –Most of the physiological signals are in the audio-frequency range or below. Also, many signals contain dc and very low frequency components.
5. The high possibility of artifacts –An artifact is undesirable signal that is extraneous to the physiological variable under measurement. This may come from electrical interference, cross talk or noise generated within the measurement system. Designers of biomedical instruments, put in ways to remove/filter or avoid these kinds of artifacts.
6. Reliability –In cases of life saving instrument like the defibrillators, their failure to operate or provide the desired output can cause a potential life threat to the patient. Hence, the biomedical equipment must be reliable, easy to operate and able to withstand physical stress like transportation within the hospital or in the ambulance and or exposure to corrosive chemicals.
7. Safe levels of applied energy –Biomedical instruments require some form of energy to be applied to the living tissue e.g. CT scan requires X-rays (a form of electromagnetic waves energy). Safe levels of some of these energies have been established by scientific researchers; designers can use this information when they are designing the medical equipment.