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  • Author Author: balearicdynamics
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Meditech: Camera probe final prototype assembly and testing

balearicdynamics

Introduction

The first camera probe prototype of Meditech has been completed and tested. It includes:

 

  • 16x2 alphanumeric LCD display
  • Set of five control buttons and one three-states position button to enable the different features and parameters, manage diagnostic tests and control the device
  • WiFi connection to the rest of Meditech networking device
  • 12 RGB LEDs ring around the camera

 

The prototype has been assembled in a custom designed container. As this probe is mainly based on visual detection there is the need to connect it to the main Meditech structure moving the probe nearby the patient. In this version the camera head (with LEDs) is fixed but a better solution should include an articulated flip movement.

 

Design

The following images shows the design components to be milled. The material is white acrylic 5 mm thick. A better solution can be reached using 3 mm thick to reach some design simplifications.

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Above: top and bottom sides.Below: the three lateral sides.

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Below: the components of the camera head enclosure and the opaline plastic cover for the LED rings. It is on a separate design as is has been milled with opaline white transparent acrylic sheet, 3mm thick

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Components

The following images shows the milled and refined components, ready for assembly. Note that the LCD display has a transparent cover protection (2mm thick plexyglas)

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Assembly

Excluding the transparent LCD protection, the camera head parts and the LED cover ring that was glued with chyanoachriate all the parts has been assembled with screws for any future modification.

Below: Raspberry PI B+ screwed on the base and the LCD protection glued on the top frame. To fix the Raspberry PI the PiFaceCAD has been removed; note the camera flat cable already molded to fit in the camera head on top of the box and the pass-through connector for the LED ring control.

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Below: the assembly steps of the camera and LED ring cables inside the guide and the back part of the camera head. The camera is kept aligned with a piece of adhesive soft strip.

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The finished camera head mounting and the sides assembled together and screwed.

Below: views of the camera head and LEDs ring in the final assembly.

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Below: views of the camera probe finished prototype

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Testing

The following images shows the camera probe testing. The test has been made with the system status displayed on the LCD (as it changes continuously), the LED ring test and the camera previewing a video without recording. The test has been left active for about 12 hours.

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Test Video

The test video shows some seconds of the 12 hours test process with the probe controlled via terminal from another computer connected to the same WiFi network.

  • in reply to DAB

    DAB,

     

    most of the case I base the final design just on seeing what's happen with the first try. One of the main problems is that you can find all the technical information but it is very difficult (at least for me) to find the dimensions of the pieces. For example the top position of the LCD and the IR hole on the PiFaceCAD mounted over the Raspberry PI has been very difficult to find correctly. In this case it is a real luck to have the mill machine to make a first try, see if all fit, correct the design then redo the job with minimal time and material possible.

     

    Enrico

  • Very nice post.

     

    I agree, for your first enclosure this is a pretty good starting point.

     

    DAB

  • in reply to fvan

    This is the first prototype, the entire project I mean. So some more "freedom" is taken in account. This is a WiFi dongle that I had here, so I have used it, as it is a standard full Linux compatible. Then starting from this prototype and architecture (I mean all the Meditech, not only this probe) there are lot of things that should be reviewed and made perfect to make the device (would be the prototype #1, first next revision) usable for on-field test. Specifically to this probe there are the following updates / issues that should be managed:

     

    1. WiFi dongle should be connected to the USB but internal, on the bottom of the probe connected with a flat cable. This will occupy part of the - not existing yet - area for batteries and recharging unit. As already mentioned in several previous posts, the question of the definitive powering will be kept in consideration at the end of the project for obvious reasons. Anyway it is not to exclude the usage of a mini-dongle like what you suggest, also because the probe should connect only to the rest of the Meditech networked components in a short range (few meters).
    2. The enclosure should be reviewed based on the actual design using ABS or acrylic plastic max 3 mm thick. Now for prototyping I am using this 5 mm thick because I have an entire closet of 5 and 10 mm plastic plus other parts like transparent plexy and more (all bought for 10 Euro)
    3. The camera head should swivel to change front/back orientation.

     

    All these details was not the worth for a prototype but it should be anyway really different than a simple bunch of cables. Also because most of the changes and upgrades to the designs are done revising the first version, that is easier, and because using the built stuff it is possible to find all ergonomy issues that can be improved.

    Another general issue that I have not yet solved until now obliging me to make this kind of prototypes is that all the measures (e.g. the holes, spacers for buttons and so on are all got by hand as there are not for these components serious data sheets including the measures nor the positions of the holes for the screws. So, better to make the holes by hand when the pieces are milled then getting precise measures and update the drawings.

     

    The following is a photo taken just now of my plastic trasure image

     

    Enrico

     

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  • Nice looking enclosure, reminds me of a photo camera image Good job milling the parts!

     

    I was wondering, isn't it possible to integrate the USB dongle as well ? Seems a bit odd to have it sticking out like that.

    If it is a wifi dongle, you could probably replace it with a low profile version.
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