Medical instruments maker Harvard Bioscience said Monday the spinoff of its Harvard Apparatus Regenerative Technology unit is complete.

Harvard Bioscience said the spinoff took effect Friday, and shareholders received one share of Harvard Apparatus Regenerative Technology, or HART, for every four shares of Harvard Bioscience they owned on Oct. 21.

Harvard Apparatus Regenerative Technology Inc. shares are now trading on the Nasdaq Capital Market under the ticker symbol “HART.”

Holliston, Mass.-based Harvard Bioscience Inc. shares will continue to trade on the Nasdaq Global Market under the ticker symbol “HBIO.”

HART develops medical devices that are intended to grow organs outside of a body for transplant. Its first product is the InBreath Airway Transplant System, which is being studied as a replacement airway in patients who have had their tracheas removed. The system is a plastic scaffold the size and shape of the patient’s trachea, and it is seeded with bone marrow cells from the patient. Because it contains bone marrow cells from the patient, the immune system won’t reject it.

Regulators have not yet approved the InBreath system. HART says it has been used in 10 successful surgeries.

David Green, the president of Harvard Bioscience, is becoming president and CEO of the new company, and Chief Financial Officer Tom McNaughton will take the same title at HART. Jeffrey Duchemin, the CEO of Harvard Bioscience, is also taking the title of company president. The company announced in October that Robert Gagnon would become is CFO after the spinoff of HART.

Harvard Bioscience also said it is eliminating the position of chief operating officer on Nov. 30. Susan Luscinski has been the company’s COO 2004. Harvard Bioscience said the responsibilities of that position will be handled by Duchemin.

Harvard Bioscience planned to spin off HART earlier this year, but postponed the move in April because of market conditions.