Ethicon Harmonic Ultrasonic Sealers: How They Work and How to Choose
Ethicon Harmonic devices are ultrasonic surgical instruments that cut and coagulate tissue at the same time using high-frequency mechanical vibration around 55,500 cycles per second rather than electrical current. The line includes open and laparoscopic shears under part numbers such as HARH36, HAR736, and HAR9F, selected by surgical approach and shaft length.
How does a Harmonic ultrasonic device work?
A Harmonic instrument converts electrical energy into ultrasonic mechanical motion at the blade, generating frictional heat that denatures protein and forms a coagulum while the blade cuts. Because it works at lower temperatures than electrosurgery and does not pass current through the patient, it produces less lateral thermal spread, less smoke, and no electrical pathway through tissue.
What vessel size can a Harmonic device seal?
Harmonic shears are generally designed to seal vessels up to 5 mm, and certain platforms seal up to 7 mm using an advanced hemostasis mode. Sealing and cutting happen in a single action, which is a key difference from devices that seal first and divide second. Always confirm the rated vessel size for the specific instrument against its Instructions for Use (IFU).
How do the Harmonic models differ?
Harmonic instruments differ mainly by surgical approach (open vs. laparoscopic), shaft length, and generation/platform. The number in the part code commonly reflects shaft length in centimeters, so a longer code suits deeper laparoscopic access while shorter open shears suit superficial procedures.
| Model | Where to view |
|---|---|
| HARH36 | View HARH36 |
| HAR736 | View HAR736 |
| HAR9F | View HAR9F |
Confirm the exact instrument type, shaft length, and generator compatibility on each product page and in the IFU before purchase.
Harmonic vs. LigaSure: what is the difference?
Both seal vessels, but they use different energy. Harmonic uses ultrasonic (mechanical) energy and cuts while it coagulates; LigaSure uses bipolar radiofrequency energy plus pressure and typically seals, then divides.
| Feature | Harmonic (ultrasonic) | LigaSure (bipolar RF) |
|---|---|---|
| Energy type | Ultrasonic vibration | Bipolar radiofrequency + pressure |
| Action | Cuts and coagulates simultaneously | Seals, then divides |
| Typical vessel seal | Up to 5 mm (up to 7 mm advanced mode) | Up to 7 mm |
| Thermal spread | Generally lower | Slightly higher |
The right choice depends on the procedure, the vessels involved, and surgeon preference. For the bipolar option, see our Covidien LigaSure buyer's guide.
Frequently asked questions
Is the Harmonic scalpel the same as electrocautery? No. Electrocautery passes electrical current through tissue, while a Harmonic device uses ultrasonic mechanical vibration and does not send current through the patient.
Can a Harmonic device cut and seal at the same time? Yes. Harmonic instruments coagulate and cut in a single action, which differs from devices that seal first and divide afterward.
What does the number in HAR736 or HARH36 mean? The number generally reflects the instrument's shaft length in centimeters; confirm the exact length on the product page.
Are Harmonic shears single-use? Most Harmonic shears are single-patient-use. Confirm the designation on the specific model's IFU.
Where to buy Ethicon Harmonic sealers
BKMedStore carries Harmonic ultrasonic shears in open and laparoscopic configurations. Browse current availability in the Staplers, Sealers and Cutters collection.
