Intro to Medical Instruments Flashcards
Unit1
Steps to Device Manufacturing
- invention
- prototype design
- product development
- clinical testing
- regulatory approval
- manufacturing
- marketing
- sale
What are some of the barriers to device manufacturing?
- FDA Approval
- Funding
- Demand or market for the product
- Practical requirements
- human barriers
- Beureaucratic bs
- inevitable setbacks
How do we allocate our resources?
time, experience, and money
How do we protect new ideas?
intellectual property agreements, patents
What are the two main product models?
evolutionary and revolutionary
What is the evolutionary product model?
a new model of an existing product that adds a new feature or improves technology also reduces the cost of production
ex: iPhones generation to generation
What is the revolutionary product model?
solves a totally new problem or uses a new principle/concept to solve an old problem in a better way than previous methods.
ex: MRNA vaccines
Measurand
physical quantity or condition that the system measures
ex: blood pressure, ECG potential, infrared radiation, blood, biopsies
Sensor
converts a physical measurand to an electric output
Transducer
a device that converts one form of energy to another
Design constraint
should only respond to the form of energy present in the measurand
ex: diaphragm converts pressure to displacement, strain gage converts displacement to an electric voltage
Signal conditioning
modifies the signal coming from the sensor output to be compatible with the display
ex: amplifying and filtering the signal to match the impedance of the sensor to the display
Output Display
must be displayed in a form that the human operator can perceive
How often should samples be taken?
factors that determine how often include: frequency content, objective of measurement, condition of the patient, and potential liability to the physician
Analog
- has a physical element to it
- continuous signal
- can be pulsed if physical signals are used
- translates directly to what is measured without modulation
Digital
- pulsed signal
- may go through digital modulation before being displayed
Measurement Constraints
- values of electric potential
- concentration
- pressure
- variability in healthy people is higher
- difficult to weed out interfering signals
Device Classification
- Quantity: pressure, flow, temp
- Principles of Transduction: resistive, capacitive, ultrasonic, electrochemical
- Organ System: cardiovascular, pulmonary, nervous, endocrine
- Clinical Specialties: pediatrics, obstetrics, cardiology, radiology
