Hi,
I search advice and good ideas with a project. I need to measure the presure precisely between a new type og cast for broken wrists and the arm to get insight into the pressure distribution under the cast. The presure must be firm but light and I am looking after a thinfilm pressure sensor that can measure under 100 gram. If there exist an aray as a sting of pressure sensors it could be fantastic, else must I build on of 4 or individual sensors.
My question is: Does anyboddy know a cheap pressure sensor or technology for 0 to 100 gram interval?
Does the pressure sensor need to be between cast and skin?
A simple drawing would help to see the details "where what how"
Something like this?
update: There is no conversion to grams in such sensor
Interesting but not easy as the 'interface' between the cast and the skin is irregular and I immagine a single sensor should be thin, small and 'soft'
As I understand this sensor should be inserted the between skin and the cast, so reusable ( or may be integrated in the cast, so every cast should have one )?
In the first case inserting/removing the sensor should result in a variation of the pressure.
In the second you can check pressure variation during the day ( or the days )
Its super complicated
I was thinking about making a pressure disk 30 mm in diameter 1 mm high with a presure area 1 mm higher in center 8 mm in diameter pressing on the thin film sensor from both sides, beacause I have been thinking about the same problem with the flexing skin.
Its a dificult project. Its just for product understanding and not for use in the finished cast product.
I agree that it would be super to have daily pressure data from use.
Pressure is not measured in grams.
It is measured in pascals. A pascal is one newton per square metre.
As one pascal (Pa) is a very small unit of pressure, you are more likely to see measurements in kPa, or even MPa.
When ur looking for an array of pressure sensors it might be helpful to buy a pressure sensor matrix or pressure sensor with your desired specifications, the way they are made is with very slim pressure sensitive film.
Any type of medical device cannot be reused! Unless refurbished by a firm certified by the FDA. At lease in the USA. My former business was contacted by a local certified refurbishing company and we could not qualify, nor did we want to go to the expense of qualifying.
It sounds like the pressure transducer you're referring to is likely from the MPX series, which are widely used for measuring pressure in various applications, including medical ones like blood pressure monitoring. The MPX5010 is a differential pressure sensor from Freescale (now NXP), and it might be what you’re thinking of due to its affordability and versatility.
These sensors are designed for low-pressure measurements and can be integrated into disposable medical devices due to their low cost, especially when purchased in bulk. They can measure pressure changes as small as those encountered in blood pressure monitoring or other similar applications.
If you're considering building a system or product involving pressure measurement, using such sensors along with simple mechanical devices like balloons can indeed be effective. The sensor's electrical output can then be read and processed by a microcontroller, such as an Arduino, to give accurate pressure readings.
Thanks I will look at the pressure Sensor and see if it can work