Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [medical]

For applications in the medical arena that will come in contact with a patient. In general these applications need to satisfy international standards such as IEC60601. These applications have stringent patient isolation constraints, capacitive leakage constraints, mode of failure constraints, and voltage or current limits that can impose considerable design limitations.

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How is a mains-connected medical device made safe against electrocuting me?

I am in physical therapy now. Some of the devices are connected to wall power, and used for muscle electrostimulation. The patient information states that no single malfunction can connect me to 230V, and any malfunction that would allow a second…
Mołot
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Is it practical for firmware to be uniquely identified in production

Are there systems available in large scale manufacturing that allow a unique serial number to be programmed into the firmware or some free memory space for each PCB that comes through? I've found that the FDA has decided to start enforcing it for…
Lukeyb
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Medical electronic devices quality

Is there a special grade for electronic components made to be used in medical devices such as life support systems? I have read in most data sheets that "this product is not to be used in life support systems". So is there a medical grade version…
User
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Circuit for small level voltage detection (microvolts)

I have been working on a project lately which help in the detection myogenic potentials (of the levels of micro-volts). After studying from several places, I finalized the following test circuit. The initial voltage dividers helps in generating the…
DodZi
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What type of ultrasonic transducers are used in medical ultrasound devices?

When I search on DigiKey for ultrasonic transducers, all I get back is the circular transducers that are sold for the various DIY projects. i.e. the picture below: However, the "medical" ultrasound devices have a wand, that houses an array of what…
KingsInnerSoul
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Designing single fault safety into class I device

I'm trying to wrap my head around safety standards for electrical equipment. My device is medical, so for me section 8 of IEC60601-1 is what really matters to me, but it's kind of my understanding that all of the safety standards (e.g. IEC60950) use…
deltamac
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Using optocouplers at the end of a twisted pair

I am designing a dumb "isolation box" that is to sit between a computer and medical data acquisition equipment. The purpose of this box is to inject power and to provide communications and digital signal isolation. The overall cable length that the…
Edgar Brown
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How do medical SMPS achieve lower Earth leakage compared to "regular" AC-DC SMPS?

When using a "regular" (i.e. not medical grade) AC-DC isolated SMPS in the following fashion, a strong mains common-mode voltage is created on the DC side due to - I believe - the stray capacitance of the isolation transformer. When attaching one of…
tobalt
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Circuit Testing, Verification & Certification Standards for Biomedical Devices

Please note: I would have posted this question on HealthIT.SE but they are apparently now closed for business, and I believe this site is the next most appropriate place to ask this. I believe this question is on topic because it involves circuit…
smeeb
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Help with finding the type of output for a mems mircophone

I am using this MEMS microphone for a stethoscope project. The data sheet recommends the following interface circuit. I can't seem to find where it states specifically that it is a differential output instead of a single-ended one. Am I right in…
EcksDeECksdeee
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Difference between a normal tactile switch/pushbutton and a detection switch/pushbutton

What is the general difference between a normal tactile switch/push button and a detection switch/push button? I have heard that if in an application, for example, a pushbutton has to be pressed for a long time (several years) until it is used,…
Lyoner
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Patient Connection Radiated Emissions problem

The company I am working for is developing a patient-connected device intended to deliver Functional Electrical Stimulation to a connected user. We are currently struggling to pass the radiated emissions standard. We have located the source of our…
John Taylor
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Make an electronic Stethoscope

I've seen some kind of electronic stethoscope that can capture heart beat rate and filter it with so many other features. Main oscope of my questoin is about capturing heart sound. There is many ways to detect muscle activities in body. But what is…
HOPE
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Any theoretical reference for empirical equation for estimating oxygen saturation (% SpO2 = 110 - 25*R)?

The empirical equation used to estimate % SpO2 is based on the observation that the ratio of the red and infrared light absorbed by arterial blood (represented by R in the equation) varies linearly with oxygen saturation. This relationship can be…
Jahir hussain
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AC filtering: Medical vs Standard Version

I am looking at that Schurter's AC power entry modules to choose a AC filtering module and at page 5 I noticed the differences between Standard version and Medical version: Their only difference is the resistor R in paraller with Cx. So the medical…
Christianidis Vasileios
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