SEARCH RESULTS FOR: Origin(62 results)
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-16-094-NS
In Commercial Distribution
- 00650551070238 ()
- Outer Diameter: 0.8 Millimeter
- Spacing 3.5 Millimeter
- Recording Depth 54.5 Millimeter
- Contact Length 2 Millimeter
- Main Tube Length 27 Centimeter
2102-16-094-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.1MM DRILL
PMT CORPORATION
2102-16-108-NS
In Commercial Distribution
- 00650551070320 ()
- Recording Depth 90 Millimeter
- Spacing 3.5 Millimeter
- Outer Diameter: 0.8 Millimeter
- Main Tube Length 27 Centimeter
- Contact Length 2 Millimeter
2102-16-108-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-16-098-NS
In Commercial Distribution
- 00650551070313 ()
- Outer Diameter: 0.8 Millimeter
- Spacing 3.5 Millimeter
- Recording Depth 90 Millimeter
- Contact Length 2 Millimeter
- Main Tube Length 27 Centimeter
2102-16-098-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.1MM DRILL
PMT CORPORATION
2102-16-107-NS
In Commercial Distribution
- 00650551070306 ()
- Outer Diameter: 0.8 Millimeter
- Spacing 3.5 Millimeter
- Recording Depth 80 Millimeter
- Contact Length 2 Millimeter
- Main Tube Length 27 Centimeter
2102-16-107-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-16-097-NS
In Commercial Distribution
- 00650551070290 ()
- Main Tube Length 27 Centimeter
- Contact Length 2 Millimeter
- Recording Depth 80 Millimeter
- Spacing 3.5 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-097-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.1MM DRILL
PMT CORPORATION
2102-16-106-NS
In Commercial Distribution
- 00650551070283 ()
- Main Tube Length 27 Centimeter
- Contact Length 2 Millimeter
- Recording Depth 68.5 Millimeter
- Spacing 4.43 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-106-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-16-096-NS
In Commercial Distribution
- 00650551070276 ()
- Outer Diameter: 0.8 Millimeter
- Spacing 4.43 Millimeter
- Recording Depth 68.5 Millimeter
- Contact Length 2 Millimeter
- Main Tube Length 27 Centimeter
2102-16-096-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.1MM DRILL
PMT CORPORATION
2102-16-105-NS
In Commercial Distribution
- 00650551070269 ()
- Main Tube Length 27 Centimeter
- Contact Length 2 Millimeter
- Recording Depth 61.5 Millimeter
- Spacing 3.97 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-105-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-16-095-NS
In Commercial Distribution
- 00650551070252 ()
- Outer Diameter: 0.8 Millimeter
- Spacing 3.97 Millimeter
- Recording Depth 61.5 Millimeter
- Contact Length 2 Millimeter
- Main Tube Length 27 Centimeter
2102-16-095-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.1MM DRILL
PMT CORPORATION
2102-16-104-NS
In Commercial Distribution
- 00650551070245 ()
- Main Tube Length 27 Centimeter
- Contact Length 2 Millimeter
- Recording Depth 54.5 Millimeter
- Spacing 3.5 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-104-NS
- Depth electrode
sEEG, PLATINUM, 14 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.1MM DRILL
PMT CORPORATION
2102-14-104-NS
In Commercial Distribution
- 00650551070221 ()
- Main Tube Length 27 Centimeter
- Contact Length 2 Millimeter
- Recording Depth 47.5 Millimeter
- Spacing 3.5 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-14-104-NS
- Depth electrode
sEEG, PLATINUM, 14 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-14-094-NS
In Commercial Distribution
- 00650551070214 ()
- Outer Diameter: 0.8 Millimeter
- Spacing 3.5 Millimeter
- Recording Depth 47.5 Millimeter
- Contact Length 2 Millimeter
- Main Tube Length 27 Centimeter
2102-14-094-NS
- Depth electrode
sEEG, PLATINUM, 12 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.1MM DRILL
PMT CORPORATION
2102-12-104-NS
In Commercial Distribution
- 00650551070207 ()
- Main Tube Length 27 Centimeter
- Contact Length 2 Millimeter
- Recording Depth 40.5 Millimeter
- Spacing 3.5 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-12-104-NS
- Depth electrode
sEEG, PLATINUM, 12 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-12-094-NS
In Commercial Distribution
- 00650551070191 ()
- Outer Diameter: 0.8 Millimeter
- Spacing 3.5 Millimeter
- Recording Depth 40.5 Millimeter
- Contact Length 2 Millimeter
- Main Tube Length 27 Centimeter
2102-12-094-NS
- Depth electrode
sEEG, PLATINUM, 6 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-06-145-NS
In Commercial Distribution
- 00650551139720 ()
- Main Tube Length 27 Centimeter
- Spacing 3 Millimeter
- Recording Depth 27 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-06-145-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.1MM DRILL, 36MM SPACING BETWEEN CONTACTS #13 & #14
PMT CORPORATION
2102-16-154-NS
In Commercial Distribution
- 00650551131496 ()
- Main Tube Length 27 Centimeter
- Spacing 3 Millimeter
- Recording Depth 110 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-154-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.1MM DRILL, 21MM SPACING BETWEEN CONTACTS #13 AND #14
PMT CORPORATION
2102-16-153-NS
In Commercial Distribution
- 00650551131489 ()
- Main Tube Length 27 Centimeter
- Spacing 3 Millimeter
- Recording Depth 95 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-153-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.1MM DRILL, 13.98MM SPACING BETWEEN CONTACTS #13 AND #14
PMT CORPORATION
2102-16-152-NS
In Commercial Distribution
- 00650551131472 ()
- Main Tube Length 27 Centimeter
- Spacing 2.43 Millimeter
- Recording Depth 80 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-152-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.1MM DRILL, 12MM SPACING BETWEEN CONTACTS #13 AND #14
PMT CORPORATION
2102-16-151-NS
In Commercial Distribution
- 00650551131465 ()
- Main Tube Length 27 Centimeter
- Spacing 1.5 Millimeter
- Recording Depth 65 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-151-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-16-143-NS
In Commercial Distribution
- 00650551131458 ()
- Main Tube Length 27 Centimeter
- Spacing 2.8 Millimeter
- Recording Depth 75 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-143-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-16-142-NS
In Commercial Distribution
- 00650551131441 ()
- Main Tube Length 27 Centimeter
- Spacing 3.5 Millimeter
- Recording Depth 85 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-142-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-16-141-NS
In Commercial Distribution
- 00650551131434 ()
- Main Tube Length 27 Centimeter
- Spacing 4.5 Millimeter
- Recording Depth 100 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-141-NS
- Depth electrode
sEEG, PLATINUM, 14 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-14-131-NS
In Commercial Distribution
- 00650551131427 ()
- Main Tube Length 60 Centimeter
- Spacing 1.5 Millimeter
- Recording Depth 47.5 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-14-131-NS
- Depth electrode
sEEG, PLATINUM, 12 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-12-131-NS
In Commercial Distribution
- 00650551131410 ()
- Main Tube Length 60 Centimeter
- Spacing 1.5 Millimeter
- Recording Depth 40.5 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-12-131-NS
- Depth electrode
sEEG, PLATINUM, 10 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-10-131-NS
In Commercial Distribution
- 00650551131403 ()
- Main Tube Length 60 Centimeter
- Spacing 1.5 Millimeter
- Recording Depth 33.5 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-10-131-NS
- Depth electrode
sEEG, PLATINUM, 8 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-08-131-NS
In Commercial Distribution
- 00650551131397 ()
- Main Tube Length 60 Centimeter
- Spacing 1.5 Millimeter
- Recording Depth 26.5 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-08-131-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-16-131-NS
In Commercial Distribution
- 00650551131243 ()
- Main Tube Length 60 Centimeter
- Spacing 1.5 Millimeter
- Recording Depth 54.5 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-131-NS
- Depth electrode
sEEG, PLATINUM, 10 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.1MM DRILL
PMT CORPORATION
2102-10-104-NS
In Commercial Distribution
- 00650551070184 ()
- Main Tube Length 27 Centimeter
- Contact Length 2 Millimeter
- Recording Depth 33.5 Millimeter
- Spacing 3.5 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-10-104-NS
- Depth electrode
sEEG, PLATINUM, 8 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.1MM DRILL
PMT CORPORATION
2102-08-104-NS
In Commercial Distribution
- 00650551070160 ()
- Main Tube Length 27 Centimeter
- Contact Length 2 Millimeter
- Recording Depth 26.5 Millimeter
- Spacing 3.5 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-08-104-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, INLINE CONNECTOR, REMOVABLE STYLET, FOR 2.1MM DRILL
PMT CORPORATION
2102-16-110-NS
In Commercial Distribution
- 00650551070139 ()
- Main Tube Length 32 Centimeter
- Contact Length 2 Millimeter
- Recording Depth 80 Millimeter
- Spacing 3.5 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-110-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, REMOVABLE STYLET, FOR 2.1MM DRILL
PMT CORPORATION
2102-16-103-NS
In Commercial Distribution
- 00650551070115 ()
- Main Tube Length 27 Centimeter
- Contact Length 2 Millimeter
- Recording Depth 68.5 Millimeter
- Spacing 4.43 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-103-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, REMOVABLE STYLET, FOR 2.1MM DRILL
PMT CORPORATION
2102-16-101-NS
In Commercial Distribution
- 00650551070092 ()
- Main Tube Length 27 Centimeter
- Contact Length 2 Millimeter
- Recording Depth 54.5 Millimeter
- Spacing 3.5 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-101-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, REMOVABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-16-099-NS
In Commercial Distribution
- 00650551070078 ()
- Outer Diameter: 0.8 Millimeter
- Spacing 3.5 Millimeter
- Recording Depth 80 Millimeter
- Contact Length 2 Millimeter
- Main Tube Length 27 Centimeter
2102-16-099-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, REMOVABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-16-092-NS
In Commercial Distribution
- 00650551070054 ()
- Outer Diameter: 0.8 Millimeter
- Spacing 3.97 Millimeter
- Recording Depth 61.5 Millimeter
- Contact Length 2 Millimeter
- Main Tube Length 27 Centimeter
2102-16-092-NS
- Depth electrode
sEEG, PLATINUM, 12 CONTACT, MINI CONNECTOR, REMOVABLE STYLET, FOR 2.1MM DRILL
PMT CORPORATION
2102-12-101-NS
In Commercial Distribution
- 00650551070016 ()
- Main Tube Length 27 Centimeter
- Contact Length 2 Millimeter
- Recording Depth 40.5 Millimeter
- Spacing 3.5 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-12-101-NS
- Depth electrode
sEEG, PLATINUM, 12 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-12-145-NS
In Commercial Distribution
- 00650551143208 ()
- Main Tube Length 27 Centimeter
- Spacing 5 Millimeter
- Recording Depth 57 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-12-145-NS
- Depth electrode
sEEG, PLATINUM, 14 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-14-145-NS
In Commercial Distribution
- 00650551143192 ()
- Main Tube Length 27 Centimeter
- Spacing 5 Millimeter
- Recording Depth 67 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-14-145-NS
- Depth electrode
sEEG, PLATINUM, 10 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-10-291-NS
In Commercial Distribution
- 00650551142485 ()
- Main Tube Length 27 Centimeter
- Spacing 3.5 Millimeter
- Recording Depth 33.5 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-10-291-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL, 27.25MM SPACING BETWEEN CONTACTS #8 & #9
PMT CORPORATION
2102-16-134-NS
In Commercial Distribution
- 00650551142461 ()
- Main Tube Length 55 Centimeter
- Spacing 3.5 Millimeter
- Recording Depth 80 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-134-NS
- Depth electrode
sEEG, PLATINUM, 16 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.1MM DRILL
PMT CORPORATION
2102-16-157-NS
In Commercial Distribution
- 00650551142133 ()
- Main Tube Length 27 Centimeter
- Spacing 3.5 Millimeter
- Recording Depth 85 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-16-157-NS
- Depth electrode
sEEG, PLATINUM, 10 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-10-155-NS
In Commercial Distribution
- 00650551139881 ()
- Main Tube Length 27 Centimeter
- Spacing 6 Millimeter
- Recording Depth 74 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-10-155-NS
- Depth electrode
sEEG, PLATINUM, 10 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-10-146-NS
In Commercial Distribution
- 00650551139874 ()
- Main Tube Length 27 Centimeter
- Spacing 5 Millimeter
- Recording Depth 65 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-10-146-NS
- Depth electrode
sEEG, PLATINUM, 10 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-10-149-NS
In Commercial Distribution
- 00650551139867 ()
- Main Tube Length 27 Centimeter
- Spacing 4 Millimeter
- Recording Depth 56 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-10-149-NS
- Depth electrode
sEEG, PLATINUM, 10 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-10-145-NS
In Commercial Distribution
- 00650551139850 ()
- Main Tube Length 27 Centimeter
- Spacing 3 Millimeter
- Recording Depth 47 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-10-145-NS
- Depth electrode
sEEG, PLATINUM, 10 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-10-148-NS
In Commercial Distribution
- 00650551139843 ()
- Main Tube Length 27 Centimeter
- Spacing 2 Millimeter
- Recording Depth 38 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-10-148-NS
- Depth electrode
sEEG, PLATINUM, 8 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-08-148-NS
In Commercial Distribution
- 00650551139836 ()
- Main Tube Length 27 Centimeter
- Spacing 2 Millimeter
- Recording Depth 30 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-08-148-NS
- Depth electrode
sEEG, PLATINUM, 10 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-10-144-NS
In Commercial Distribution
- 00650551139829 ()
- Main Tube Length 27 Centimeter
- Spacing 1 Millimeter
- Recording Depth 29 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-10-144-NS
- Depth electrode
sEEG, PLATINUM, 8 CONTACT, MINI CONNECTOR, REMOVEABLE STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-08-145-NS
In Commercial Distribution
- 00650551139812 ()
- Main Tube Length 27 Centimeter
- Spacing 3 Millimeter
- Recording Depth 37 Millimeter
- Contact Length 2 Millimeter
- Outer Diameter: 0.8 Millimeter
2102-08-145-NS
- Depth electrode
sEEG, PLATINUM, 10 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-10-094-NS
In Commercial Distribution
- 00650551070177 ()
- Outer Diameter: 0.8 Millimeter
- Spacing 3.5 Millimeter
- Recording Depth 33.5 Millimeter
- Contact Length 2 Millimeter
- Main Tube Length 27 Centimeter
2102-10-094-NS
- Depth electrode
sEEG, PLATINUM, 8 CONTACT, MINI CONNECTOR, PERMANENT STYLET, FOR 2.4MM DRILL
PMT CORPORATION
2102-08-094-NS
In Commercial Distribution
- 00650551070153 ()
- Outer Diameter: 0.8 Millimeter
- Spacing 3.5 Millimeter
- Recording Depth 26.5 Millimeter
- Contact Length 2 Millimeter
- Main Tube Length 27 Centimeter
2102-08-094-NS
- Depth electrode