Wallace H. Coulter

Wallace Henry Coulter (February 17, 1913 to August 7, 1998) was an American electrical engineer, inventor and businessman. He devised the Coulter principle, a way to count and size particles in a liquid by the dip in electric current that each one causes as it passes through a small aperture, and with his younger brother Joseph R. Coulter Jr. he built the first commercial Coulter counter and the company that sold it.^[1] He was an inventor or co-inventor on 85 US patents, wrote one technical paper, and never finished his engineering degree.^[2] The company, which became Coulter Corporation, was privately held until October 1997, when it was sold to Beckman Instruments to form Beckman Coulter.^[3] Coulter died the next year. He had arranged for $100 million of his share of the proceeds to go to the company's employees, and the remainder funded the Wallace H. Coulter Foundation.^[4]

The principle is the ancestor of resistive pulse sensing, the technique behind nanopore instruments. Molecular Reality Corporation places its own work in that line and has said, in a post on its members' site, that the Coulter brothers "should have won a Nobel prize".^[5]

Coulter was born in Little Rock, Arkansas, the son of Joseph R. Coulter, a train dispatcher, and Minnie May Johnson Coulter, an elementary-school teacher. He grew up in McGehee, in Desha County, and graduated from McGehee High School.^[6] He spent a year at Westminster College in Fulton, Missouri, and then studied electrical engineering at the Georgia School of Technology in Atlanta, which was renamed the Georgia Institute of Technology in 1948. The Great Depression ended his studies before he had a degree.^[6][7]

Coulter joined General Electric in 1937 as a sales and service engineer in the Chicago area. In December 1939 he went to the Far East in the same role for the company's X-ray business, and was based in turn in Manila, Shanghai and Singapore.^[6][1] On visits to hospitals he saw technicians counting blood cells by eye on hemocytometers. On December 8, 1941, on his way back to Singapore from hospital visits in Java, he watched the first Japanese bombing of the city. He started for home in February 1942, by way of Java, Mumbai, Dar es Salaam, South Africa and Argentina, and reached New York on Christmas Day 1942. A letter to his parents from Mumbai says of the raids that "when they came at all hours and for from 30 minutes to three hours at a time it got damn annoying", and that the only damage was "getting my knees and hands skinned diving into a ditch once".^[1]

For the rest of the war he supervised radio transmitter design at Press Wireless, Inc., in Hicksville, Long Island. In 1945 he proposed an electromedical development group in Chicago for Raytheon Manufacturing Company and briefly co-managed it, but the proposal was never formalized, and he began designing a noise-cancelling amplifier for electrocardiography as a personal project.^[8]

In Graham's account the atomic bombings of Hiroshima and Nagasaki in August 1945 gave Coulter his purpose. He wanted blood counts that were rapid, accurate and repeatable at short intervals, so that the recovery of bone marrow in people exposed to radiation could be followed. A manual count took a technician 15 to 30 minutes and was uncertain by about 16 percent for red cells and 21 percent for white cells.^[1] Joseph, who was eleven years younger and had spent the war in Army training and signal work, joined him.^[8]

On July 26, 1948 Coulter wrote the first statement of the principle, and on October 16, 1948 he showed that blood cells changed a current flowing through a hole that he had burned with a needle in a cellophane wrapper from a pack of cigarettes.^[7] Patent attorneys to whom he described the idea told him repeatedly, "You can't patent a hole."^[7] The application was filed on August 27, 1949, and US 2,656,508 was granted on October 20, 1953.^[7][9]

The Office of Naval Research paid for the first working counters. The brothers' one contract with the office brought $17,769.42 in federal money, and under the office's guidelines Wallace kept ownership of the early patents and was free to publish. Graham sets that sum beside the $2,000,000,000 in federal funds spent on the Manhattan Project.^[2] Coulter described the Model A counter on October 3, 1956 at the National Electronics Conference in Chicago, in a paper titled "High speed automatic blood cell counter and cell size analyzer".^[10][11] It reported counts of some 50,000 cells at about 3,300 cells a second, against perhaps 20 minutes for a manual count of 500 cells. It was his only published paper. In 2000 it was selected as one of the 86 most influential hematology papers of the twentieth century.^[2]

On April 14, 1958 the brothers dissolved their family partnership and incorporated Coulter Electronics, Inc. Joseph became president and Wallace vice president.^[12] By April 1960 the brothers had placed more than 750 Model A counters for clinical and biological work, and 101 more through a sales franchise for industrial use.^[12] The company moved from Chicago to Hialeah, Florida, in December 1961.^[13] Its Model S of late 1968 printed seven blood parameters from one sample in under a minute, and by 1988 the Coulter companies had built the 80,000th instrument based on the principle.^[4]

On April 26, 1986 Reactor Unit 4 at the Chernobyl Nuclear Power Plant exploded. On May 5 Coulter authorized the donation and airlift from France to Moscow of a Coulter S-Plus IV hematology analyzer and reagents for 5,000 complete blood counts, for the treatment of radiation victims. More Coulter instruments followed. Graham writes that Coulter would sometimes speak with quiet pride of the application of his needle-made aperture to the need he had seen some forty years earlier.^[4]

In 1991 the brothers merged Coulter Electronics into Coulter Corporation. Joseph died on November 27, 1995. Coulter's declining health then led to the sale of the corporation to Beckman Instruments, which took control on October 31, 1997 for $875 million in cash plus assumed obligations.^[4][3] Coulter died on August 7, 1998, after arranging for $100 million of his share of the proceeds to be distributed to the corporation's roughly 5,500 employees according to their position and length of service.^[4] The Wallace H. Coulter Foundation received its funding from his estate in 1998.^[14] He never married and had no children.^[6]

Graham describes Coulter as modest and often self-effacing, an engineer who documented his progress and left its promotion to others. His patents record decades spent on the small interacting effects that limited the performance of the Coulter principle in practice, and his last three were issued after his death, five of the 85 being shared with Joseph. He liked to explain technical details to anyone who would listen, competitors at trade exhibits included, and much of what he understood was recorded only in notes that are now mostly lost.^[2]

Coulter was selected for the John Scott Medal by the City of Philadelphia in 1960 and received it that December.^[13] The IEEE gave him its Morris E. Leeds Award in 1980.^[15] He received honorary doctorates from Westminster College in 1975, the University of Miami and Clarkson University in 1979, and Barry University in 1991, and, after his death, a doctorate of philosophy from the Georgia Institute of Technology in 2005. The National Academy of Engineering published a memorial tribute in 2001, and he was inducted into the National Inventors Hall of Fame in 2004.^[2] The joint biomedical engineering department of Georgia Tech and Emory University carries his name.^[16]

A 2013 paper by M. D. Graham of Beckman Coulter, titled "The Coulter principle: Imaginary origins", checked the usual accounts of the invention against the surviving documents.^[17] The needle, the cellophane, the cigarette pack and the radiation motive are all in the records.^[1][7] The essay that introduces Epic Quest Bio tells the invention in the second person, with the brothers "in a makeshift lab in the basement of your home in Chicago in 1948", and says of Coulter: "Outrageously, you didn't win a Nobel Prize in Medicine for it."^[18][a] The same essay says that almost all the instruments that perform the complete blood count "are still, essentially, Coulter Counters". Modern hematology analyzers measure cells by electrical impedance, by optical methods, or by both.^[19]

• Coulter counter
• Coulter principle
• Joseph R. Coulter Jr.
• Beckman Coulter
• Resistive pulse sensing
• Rain of blood (demonpore)

• Graham, M. D. (2003). "The Coulter principle: Foundation of an industry". JALA: Journal of the Association for Laboratory Automation 8 (6): 72-81. doi:10.1016/S1535-5535-03-00023-6.
• M. D. Graham (2020). "The Coulter Principle: For the Good of Humankind (full text)". Engineering and Technology History Wiki.