Insertion mechanism for foetal scalp electrode - has coupling between electrode head and outer sleeve ruptured by relative rotation

摘要

The electrode insertion mechanism has an inner sleeve to which the electrode head (55) is attached and an outer sleeve (56) within which the inner sleeve and the electrode head are displaced and to which the electrode head is secured via a coupling which is ruptured by relative rotation of the electrode head. Pref., the rotation is provided via a knob at the outer end of the inner sleeve, the coupling between the electrode head and the outer sleeve pref. comprising a number of radial spokes (57a, 57b) which are ruptured when the applied torque exceeds a given limit. ADVANTAGE - Rupture of coupling between electrode head and outer sleeve is detected for signalling correct attachment.