A catheter placement system configured for accurately placing a catheter within the vasculature of a patient, the catheter placement system comprising for improving catheter placement accuracy: 1) an ultrasound-assisted guidance system for introducing the catheter into the patient's vasculature; 2) a magnetically-based tip location system for tracking of the catheter tip during its advancement through the vasculature path; and 3) an ECG signal-based catheter tip guidance system to enable guidance of the catheter tip to a desired position with respect to a node of the patient's heart from which the ECG signals originate, the ECG signal-based catheter tip guidance system including means for passing ECG signals from the catheter disposed in a sterile field of the patient to a tip location system sensor disposed in a non-sterile field separated from the sterile field by a sterile barrier, the catheter placement system further comprising a tether conveying ECG signals from the catheter to the tip location system sensor, the tether being operably connected to the tip location system sensor via a tether connector, the tether connector including one or more piercing contacts for piercing the sterile barrier (640A, 640B), wherein the one or more piercing contacts are respectively included on slide arms (642A, 642B), and a portion of the tip location system sensor including one or more corresponding contact receptacles (644A, 644B), wherein the system is configured such that the sterile barrier is interposed between the tether connector and the portion of the tip location system sensor. 1) an ultrasound-assisted guidance system for introducing the catheter into the patient's vasculature; 2) a magnetically-based tip location system for tracking of the catheter tip during its advancement through the vasculature path; and 3) an ECG signal-based catheter tip guidance system to enable guidance of the catheter tip to a desired position with respect to a node of the patient's heart from which the ECG signals originate, the ECG signal-based catheter tip guidance system including means for passing ECG signals from the catheter disposed in a sterile field of the patient to a tip location system sensor disposed in a non-sterile field separated from the sterile field by a sterile barrier, the catheter placement system further comprising a tether conveying ECG signals from the catheter to the tip location system sensor, the tether being operably connected to the tip location system sensor via a tether connector, the tether connector including one or more piercing contacts for piercing the sterile barrier (640A, 640B), wherein the one or more piercing contacts are respectively included on slide arms (642A, 642B), and a portion of the tip location system sensor including one or more corresponding contact receptacles (644A, 644B), wherein the system is configured such that the sterile barrier is interposed between the tether connector and the portion of the tip location system sensor. the ECG signal-based catheter tip guidance system including means for passing ECG signals from the catheter disposed in a sterile field of the patient to a tip location system sensor disposed in a non-sterile field separated from the sterile field by a sterile barrier, the catheter placement system further comprising a tether conveying ECG signals from the catheter to the tip location system sensor, the tether being operably connected to the tip location system sensor via a tether connector, the tether connector including one or more piercing contacts for piercing the sterile barrier (640A, 640B), wherein the one or more piercing contacts are respectively included on slide arms (642A, 642B), and a portion of the tip location system sensor including one or more corresponding contact receptacles (644A, 644B), wherein the system is configured such that the sterile barrier is interposed between the tether connector and the portion of the tip location system sensor.