A hybrid ADC having a successive approximation register ADC mode for generating a bit of a digital signal and a ramp ADC mode for generating an additional bit of the digital signal is disclosed. A patient support surface is configured to couple to the bed support. Recovery capability is maximized and the packet loss is reduced in such a situation that less number of ACKNACK signals are fed back than that of downlink packets. A master object is provided and is the focal point of a user’s interaction with the framework. The transistor further includes a first diffusion region and a second diffusion region to provide a channel region in the body region between the first diffusion region and the second diffusion region. If use is made here of two lifting cables, each of these lifting cables is led over a pulley block and, in order to achieve the same loading capability if use is made of just one lifting cable, the latter is led, in addition, over a floating pulley which is mounted between the two pulley blocks, the two pulley blocks also being secured against tilting.