einstichinstrument for the study of living body

摘要

The trocar for endoscopy of the abdominal cavity has a body (1) with a sharp point (2) which penetrates the skin (7) of the patient. Mounted on the surface of the sloping tip are pressure sensors (4) connected to an indicator (5) at a remote point, giving a signal as the tip is inserted. The sensors are connected to the indicator by wires (6) passing through the body of the device. In the event of a fall in pressure, an audible alarm can be sounded. The device can be connected to a circuit with a ref. signal generator and a comparator so that an indication is obtd. when the recorded pressure rises above or falls below a determined level. Alternative designs have different patterns of pressure sensors arranged at the tip and along or around the body behind the tip.