"Metastasis is responsible for > 90% of cancer-related deaths. Billions of dollars have been spent trying to cure primary tumors but very little was spent in trying to detect or kill the highly aggressive tumor cells that cause disease spreading. One of the reasons is that single cell studies of rare cells in blood still present a large challenge. Single cell analysis remains tedious with many different instruments and protocols, typically taking a few days of hands-on work. This slows down research, but also hinders the translation to application in future clinical practice. In SCALPEL, we envisage a high-content, high-throughput cell imaging and sorting platform, more compact and easier to use than any existing single cell analyzer. The high content results from lensfree digital imaging of single cells on a high speed CMOS active optical pixel matrix to analyze the morphology of cells. The high throughput results from a highly parallelized fluidic matrix that steers cells at high speed over the CMOS imaging blocks. Lensfree cell sorters can be realized in a cheap and compact platform, as all optomechanical components (lenses, detectors, nozzles,...) are replaced by nanoelectronics, advanced imaging and signal processing technology.SCALPEL aims to perform a full feasibility study of this concept and will require to investigate the ultimate limits in: 1) maximizing image resolution and sensitivity to single cell morphological features obtained via lensfree holographic imaging; 2) maximizing cell manipulation speed in microfluidic systems via a high degree of parallelization; and 3) digital image signal processing with extremely low latency at reasonable power consumption. If this multidisciplinary complexity can be understood, we will have built the components for different versions of compact cytometers that can be used at hand of pathologist, surgeons, and nurses for improving the individualized follow-up and survival rate of cancer patients."