Introduction Flashcards
medical device
apparatus for diagnosis/therapy that does not attain its primary purpose through chemical action
diagnosis
identification of the nature and cause of disease
Mitigation
alleviation of the course of a disease
therapy
treatment of a disease
prevention
interposition of an obstacle to a disease
Medical instrument
medical device that makes measurements
Describe flow chart of medical instrument
Patient -> Transducer -> Display
what is an isolation/isolater
patient isolation is positioned before or after the sensor to prevent the patient from receiving an electric shock
What is analogue
continious signal, no computer involved. ex// voice, sound waves
What is digital
takes measurements of analogue signal and converts it to digital data
Analogue prefilter
makes signals (like music or other info) cleaner before they process or use them
what is ADC
analogue to digital converter, makes analogue signal readable for machines
digital filter
filters out wanted digital measurements
Downsampling
reduces the number of data points by skipping some, making the data smaller or simpler
Input dynamic range
a device is only sensitive to a specific range of input AMPLITUDES. If a signal is too small, It will be missed. It it too big, it will be clipped
What is frequency response
a device is only sensitive to a specific range of input FREQUENCIES. If a signal frequency is too low, It will not be heard. It it too high, it will not be heard.
what is accuracy in measrements
the closeness of the measured values to the true value, taking into consideration both precision and bias
What is bias in making measurements
the difference between the mean measured values and the true values
what is the precision aspect of making measurements
the standard deviation of the measurements
Describe high accuracy, high precision on bullseye
all spots together in middle of bulleyes
Describe low accuracy, high precision on bullseye chart
all spots together, far from the bulleye middle
Describe high accuracy, low precision on bullseye chart
spots far apart, close to bullseye middle
Describe low accuracy, low precision on bullseye chart
spots far apart, far from bullseye middle
What are the 4 types of sensors
- surface electrodes
- pressure sensors
- thermistors
- photodiodes
what are surface electrodes + what are they made of
sensor that converts ionic current in body to electrical current.
occurs through the creation of a double layer of charge at the electrode-electrolyte interface (electrode-metal, electrolyte - goo)
Usually uses KCl
Describe the 3 lead placement of ECG and describe why each lead is placed where it is
RA - RED near right shoulder
LA: YELLOW near left shoulder
LL: GREEN lower left side
RA to LA covers whats going on between two arms (heartbeat) and LL captures whats common to everything (tells us what to filter out)
Describe pressure sensor
we wish to measure mechanical action changes in the body as pressure in mmHg
what is thermister
a thermal resistor that is used to measure temperature
what is photodiode
light detector that use used to measure changes in light waves that have interacted with the body (ex//fitbit LEDs)
What is quantization
a computer w more storage is able to store more bit allowing for more colour and detail in the data. more bit = more detail=more expensive
what is max frequency for humans
40k
what is sampling
when converting analog signal to digital, the signal needs to be sampled. ec//listening to music and writing down amp of every sound
What is nyquist sampling theorem
sampling frequency = 2(fmax)
Describe some of the risks of using an AI for diagnosis.
AI in medical diagnosis poses risks such as misdiagnosis, bias, lack of explainability, over-reliance by doctors, data privacy concerns, legal uncertainty, and ethical issues, which can impact patient safety and trust.
describe what is meant by an AI being a “black-box.”
A “black-box” AI is a system that makes decisions without providing clear explanations, making it difficult to understand or trust its reasoning.
