Provided is a non-invasive blood measuring device comprising: a fixture which in part or in whole is buried in bone tissue of a patient; an abutment provided in a space inside the fixture; a sensing unit including biosensors for measuring a substance in the blood; a filter through which the substance in the blood to be measured is passed through; and an outcall unit.

Among others, the present invention provides devices each including a micro-filter, a shutter, a cell counter, a selector, a micro-surgical kit, a timer, and a data processing circuitry, wherein the micro-filter is capable of detecting or filtering circulating tumor cells.

Among others, the present invention provides apparatus for interacting with a biological subject to detect circulating tumor cells therein, comprising one device for sending a signal to the biological subject and optionally receiving a response to the signal from the biological entity.