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Standard versions of blood separators typically use medium-price color sensors for a detection of a boundary level between red blood cells and plasma, at the last gate – at hose clamps. Discrete number of sensors is related to a number of significant levels to be detected thus making blood separation potentially faulty and unreliable. Our target was to make flexible, low cost replacement for level detection system that can be easily integrated into the existing product. We came up with an image processing solution that uses USB web-camera, ARM based off-the-shelf board – BeagleBone black and free OpenCV library. Flexibility is held in much higher, selectable number of levels, freely positioned USB camera and brand-free independent processing platform, as well as semi-automatic calibration system. By adding minimum additional electronics, we managed to integrate our solution into existing Blood processing machine. In conclusion, we added a new value to the machine at lower cost in production, increasing measurement frequency and resolution needed for improvement of blood separation process. Next step is to try to use two USB cameras on a custom-made board, for simultaneous level detection on two-channel blood separator, bringing the system integration to the higher level.

Haptics covers many different forms of mechanical interaction with human senses by engaging, touch, vibrations and forces/torques, established for the purpose of augmenting the feedback structure during human-machine interaction. A haptic device has mechanical part, moved by actuators from one and human hand or fingers from the other, actuators, drives, sensing elements, as well as algorithms designed to control the interaction between human and machine in positioning and motion control tasks. With such a system, motors can be controlled in a way to simulate various environments, defined by their material and dynamics, for example pushing soft ball uphill. Haptic devices are becoming more popular in medical applications after introduction of modern medical robots with many different extensions for minimally invasive surgery or diagnostics based on palpation. This paper discusses one DC motor driver custom designed for the purpose of designing a haptic device for medical applications.

The paper describes a low cost force sensor system ready to be evaluated in force-feedback joystick designed for a medical haptics application. It is based on low-cost parts from home appliance scale with strain gauge technology, and of-theshelf IC instrumentation amplifier. The development process, electronic circuitry and designed software are presented. Experimental results give a good ground to believe that this approach can provide sufficient quality in further development of human-machine interaction algorithms.