Lecture 1.2. Flashcards
Why does patient monitoring vary?
Because it depends on the patients condition and how urgent the required monitoring is
How can patient monitoring vary? Three areas
In the home or clinic, it may be infrequent and irregular to check for long term changes or diagnose a fresh condition
In a regular ward situation, it may require specific consumables eg. Probes
In critical areas (ICU, CCU, HDU), it will be continuous
What are the different characteristics of patient monitoring technologies? What may they have/be?
Invasive or non invasive
Configured to different parameters
May require specific consumables - probes
May be mobile - battery issues
May network to a central station: hardwire can bring fabric issues and wireless can bring EMC issues
May have on board ‘trend’ storage but now, more commonly, long term remote storageb
Why are trends important for patient monitoring devices?
Parameters may change slowly within critical limits
To predict and prevent critical situations
Monitoring trends over a period - a day or many can help
Algorithms and AI can be used to help the clinical staff and flag dangerous trends
Analysis usually completed and reviewed at a central station
Patient monitoring devices are used for different situations, what would one need for being beside?
Large clear display
Alarm limits preset
May be networked to a nurse station
Infrastructure issues - any challenges related to the physical/technical setup
Wireless can be used
Patient monitoring devices are used for different situations, what would be needed for transportation?
High capacity battery
Bed or cart mounted
Long term
Long term patient data trends can be transferred between monitors
What are the main vital signs to be taken for a patient monitoring device?
Body temperature
Pulse rate
Respiration rate
Blood pressure
SpO2
What parameters are needed for critical monitoring?
SpO2
ECG
pulse rate
Respiration rate
Blood pressure
Temperature
CO2
Anaesthetic gases
Bispectral index
What makes the temperature rise in the body?
If it’s fighting infection
What can be temperature be used for with respect to patient monitoring?
Warn changes in the patients condition
as a threshold for intervention
What is the temperature of interest?
Core temperature
When can measuring core temperature be done?
Cardiac surgery as it is invasive
What types of probes are used to measure core temperature during surgery under anaesthetic?
Naso-pharangeal
Where is the simplest place to check temperature on a patient? Are there any issues with this? If so, do tell
Hand or patients forehead
Yes, subjective and not calibrated
What has replaced glass thermometers? And what do they need?
Tympanic (in ear) IR thermometers
Some are temporal lobe IR thermometers
Need disposable covers
Why have glass thermometers been replaced by tympanic IR and temporal lobe IR thermometers?
Safety - mercury and glass free
Easy to read - digital
Robust
Why is using tympanic IR and temporal IR thermometers not the golden standard?
Issues of comparability in use remain
What was mercury replaced by in a glass thermometer?
Galinstan - mixture of gallium, indium and tin
What is the difference between an active and passive device? And give an example for each for temperature
Active - provides a voltage as temperature changes. This voltage allows us to measure the temperature eg. Thermocouple
Passive - the resistance changes, with temperature. Apply a fix voltage and measure the current to read out the temperature
How can resistance be used to measure temperature changes?
Resistance changes with temperature
Resistance of a metal increases with temperature
Define a thermistor, and what is the advantage and disadvantage of it compared to a resistor
A semiconductor device whose resistance generally decreases with temperature
Can be more precise than a resistor, not linear over such a large range of temperature as a resistor is
Define a thermocouple
When 2 different metals are joined together, an electric potential is developed (thermocouple effect)
There are 2 junctions in the thermocouple circuit, one is kept at a reference temperature and the other used to measure the test temperature
Depending on the difference in temperature, a voltage is generated and the resulting currents is calibrated for temperature
How can a thermocouple increase its sensitivity?
Adding a thermopile
What is a thermopile?
Number of thermocouples in combination, usually in series
