Oral-History:Léandre George Pourcelot

Léandre George Pourcelot.jpg

About Léandre Pourcelot

Léandre Pourcelot, PhD, MD, is now retired. He was born on September 7, 1940, in Orchamps-Vennes, France. He obtained the electrical engineering degree from the Institut National des Sciences Appliquées, INSA Lyon, France, in 1963, and a Ph.D. in 1967. He completed medical studies and obtained the MD degree from the medical Faculty at the University of Tours in 1977, where he also obtained a degree in nuclear medicine in 1980. From 1980 to 2006, he was Professor of Biophysics, Francois Rabelais University, Tours, France, (http://www.univ-tours.fr) and Head of the Department of Nuclear Medicine and Ultrasound at the University Hospital (http://www.chu-tours.fr)

He began his professional career in 1963 as a researcher at INSA, Lyon, where he developed the first European ultrasonic Doppler velocimeter. In 1968, he joined the Faculty of Medicine in Tours, France, where he was assistant, associate, and then full Professor. He also was director of the Group of Public interest GIP “Ultrasound” and of the INSERM research Unit 316. www.inserm.fr

His research activities dealt with ultrasonic instrumentation and clinical applications, and he was principal investigator of several studies in the field of space physiology. In 1972 he and his research group developed one of the first real-time ultrasound imaging systems based on the electronic scanning of a linear array. Pourcelot was also one of the pioneers in clinical Doppler vascular research. In 1974 he described the "Resistance Index" or the "Pourcelot index". In 1977 he described pioneering work on colour-coded Doppler images. He led a team of researchers and clinicians who had devised important and creative experiments in the application of Doppler ultrasound in adult vascular diseases as well as in the assessment of foetal conditions, and designed many innovative apparatuses for the purpose. They were also responsible for important pioneering works on space physiology and medicine (1982-2000), including the first echograph used on board of a space vehicle (1982). Other works included the use of high frequency ultrasound transducers, and techniques in the study of newborn cerebral function, physiology and pathophysiology, and with particular reference to the preterm baby.

Pourcelot co-founded several industrial companies, as well as the French Society for Ultrasound in Medicine and Biology (1972) www.sfaumb.fr, the French Doppler Club (1975) and more recently (2004) the Planiol Foundation www.fondation-planiol.fr He is a member of WFUMB, and was president and member of a large number of learned societies.

In 1995 Pourcelot received the prestigious IEEE Judith A. Resnik Award for his work on ultrasound imaging in the measurement of cardiovascular systems during space flight. In 2003, he was honoured with the Ian Donald Gold Medal for Technical Merit from the International Society of Ultrasound in Obstetrics and Gynaecology (ISUOG).

About the Interview

The interview conducted by Ayache Bouakaz, Inserm and University of Tours at Léandre Pourcelot’s home in Veigné, France on Wednesday 12th February 2020. Strong and kind help of Jean Philippe Letourneur and Jean-Marc Grégoire is highly appreciated.

Interview #845 for the IEEE History Center, The Institute of Electrical and Electronics Engineers, Inc.

Copyright Statement

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Request for permission to quote for publication should be addressed to the IEEE History Center Oral History Program, IEEE History Center at Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030 USA or ieee-history@ieee.org. It should include identification of the specific passages to be quoted, anticipated use of the passages, and identification of the user.

It is recommended that this oral history be cited as follows:

Léandre Pourcelot, an oral history conducted in 2020 by Ayache Bouakaz, IEEE History Center, Hoboken, NJ, USA.


Interviewee: Léandre Pourcelot

Interviewer: Ayache Bouakaz

Date: 12 February 2020

Location: Veigné, France

Family and Early Life, Childhood


My name is Ayache Bouakaz I'm here with Léandre Pourcelot in his home in Veigné, next to Tours city, France. Léandre is one of the fathers of ultrasound imaging, specifically Doppler ultrasound.

I’m here to do the interview for the Oral History of his career and life for the IEEE.

Thank you Léandre for welcoming us in your home for the IEEE interview.

Léandre, would you please introduce yourself by stating your full name, the date and place of birth?


I was born in France in 1940 into a family of 10 children in a hamlet of 8 houses located in the Jura Mountains, near the Swiss border. My parents were farmers and fed cows to produce butter and Comté cheese. We also had a small fir forest for construction and firewood. In the area where we lived, at an altitude of 800 meters, it was very cold in winter with temperatures that could drop to minus 30 degrees Celsius. Our house had only one heated room. Actually, the best place in winter was the stable in which we had 20 cows and 3 horses. We lived 5 km from the primary school so that every day we had around 10 km to walk to and from school often in the rain and snow.


Can you tell us about your undergraduate and graduate studies?


At the age of 11 years old, I successfully passed the entrance exam to the high school Lycée Victor Hugo of Besançon city in which I became boarder for 7 years. In this school we were more than 1000 students and around 650 boarders. I had chosen to learn Latin and German, as well as mathematics and physics. Sport was a way for me to support boarding school. I practiced athletics (100m, throwing disc and javelin, triple jump) and football. I could play football both in the high school team and in a local team named Cercle Suisse (Swiss Circle) in which I quickly became the captain. When I was 15, I also managed with 2 other students the cooperative of the high school. It was a way to provide students with school supplies and sweets.

At the end of my secondary studies I would have liked to study medicine, but it was too long and too expensive. I could successfully apply for a new engineering school in Lyon called INSA (National Institute for Applied Sciences). At INSA I chose an electronics engineer training in electronics. Thanks to this training, I had the chance to experience an important period of switching from electronic tubes to transistors.

Professional Soccer Player or Electrical Engineer


In your primary school, you had to do lots of walking, but also you practiced different sports in middle school. You mentioned that you practiced soccer in high school and at some point in time, you had to make a choice between becoming a professional soccer player in Lyon or an electrical engineer? That was an easy or difficult choise?


When I arrived at INSA, I was contacted by the Lyon football team to be one of the future professional players. Unfortunately the conditions were not favorable enough for me to be able to carry out in parallel high level studies and a professional sport. However, I continued to play football in amateur teams until the age of 60.



You started your PhD at INSA Lyon. So what was your PhD topic and why did you choose that topic?

Doppler Ultrasound (Lyon 1963-1967)


In June 1963, I finished my studies in Electronic Engineering at INSA and I was proposed a position of Assistant (teacher and Researcher) in the Department of Physics at the same School of Engineers. In October 1963, I had to propose a research project for my thesis of Doctor in Engineering (PhD).

As the laboratory was repeatedly asked by the vascular surgeons of the University Hospital of Lyon to develop a blood flow meter for vascular surgery, I started a bibliography study in the field of electromagnetic and ultrasonic means for measuring flow and velocity. I therefore discovered the very first papers published on Doppler by Satomura, Kaneko, Kato, Franklin and coll. from 1959 to 1961. I rapidly started the development of a non-directional continuous wave Doppler, which was functioning in late 1964. This was the first Doppler system developed in Europe. This device was not safe enough for use on human because of the acoustic energy (200 mW/cm²) needed to have a good signal, but showed promised results in experimental surgery. We therefore developed sensitive perivascular probes which could be sterilized and implanted in animals over a period of a month. The acoustic energy needed was less than 50 mW/cm², which was low enough to avoid any hemolysis. The very first recording made on human was performed in early 1965 on an arterio-venous bypass in Teflon placed on the radial artery for hemodialysis. From 1965 to 1967 the Doppler device was used in many fields of vascular surgery in human as well as in experimental surgery, for transplantation of heart, the kidney, the liver and even for pharmacological studies in dog, pig, sheep and cow. We succeeded to publish the first paper was published in a french journal, Compte-rendus de l’Académie des Sciences, Paris, in 1965.

Commercial Directional Continuous Wave Doppler and the Resistance Index or Pourcelot Ratio


After your PhD in Lyon, you moved to Tours to start an ultrasound lab. Can you explain the context and the objectives? Who convinced you to move?


Having got the title of Ph.D. with a thesis entitled “Study and development of a Doppler blood flow meter: its use in telemetry”, I moved, in January 1968, to the University Hospital of Tours, in the team headed by Professor Thérèse Planiol (Department of Biophysics). Thérèse Planiol was one of the first woman in the world involved in the development of Nuclear Medicine and in the use of Ultrasound in neurology (echoencephalography). In her lab I could finish the development of a directional C.W. Doppler device, the first in Europe, which was immediately proposed for commercialization.

For that purpose we created Delalande Electronique Company and exhibited a commercial unit at the 1st World Congress on Ultrasound in Medicine and Biology, Vienna, Austria, in 1969. In the meantime, I had the opportunity to study velocity curves in normal subjects and in patients with carotid lesions, arteriovenous aneurysms and arteritis.


What about the Pourcelot index?


The characterization of blood flow in cerebral vessels was a problem because we were unable to measure the blood flow volume transcutaneously. Therefore we needed parameters linked to blood flow or peripheral resistance, easy to determine, and independent of the angle of incidence of the Doppler beam. Together with Th. Planiol, we observed that the physiological diastolic flow D into the arteries supplying the brain was drastically decreased in pathological cases with arterial obstruction.

In order to determine a parameter which was varying the same way as the resistance, into finite limits, in 1972 we proposed the ratio R = (S−D)/S (S : max. systolic velocity, D : end diastolic velocity) which was called resistance or resistive index (Traité de Radiodiagnostic, Masson Editor, 1972). This resistance index is now frequently called “Pourcelot ratio”.

Ultrasound in Space


Among the various ultrasound devices you have developed, one of them was flown to space. That’s a big achievement! How did this adventure start?


In 1975 I was asked by the CNES (French National Agency for Space) to participate in a French-Soviet meeting where we discussed the possible use of ultrasound for monitoring cerebral blood flow in cosmonauts (Russian astronauts). Few years later, a common French-Soviet mission on board the Saliut 7 space station was decided by the governments of USSR and France. A proposal of our lab for the ultrasonic study of the cardiovascular system onboard the soviet space station was selected by the CNES and the soviet agency. This decision was based on our scientific program and also on the fact that we had experience in the development of ultrasonic prototypes and in the manufacturing of ultrasonic probes. Following this decision, our laboratory had the opportunity to develop the first echo-Doppler space device for the surveillance of the cardio-vascular system of astronauts during a space flight. Thanks to this first space echo-Doppler I have been “principal investigator”, first on the Salyut 7 soviet space station in 1982 (common Soviet-French mission (JL Chrétien)) and 1984. The 1984 mission had the world record of 237 days in space by 3 cosmonauts, and secondly on the American space shuttle in 1985. In this mission, French astronaut P Baudry was onboard. Our device was tested on six astronauts pre-, in- and post-flight.

Based on these first experience of the use of an echo-Doppler in weightlessness, we developed a new and compact machine in the period 1984-85. We called it “As de Cœur” (“Ace of Heart”). It was flown onboard the MIR Soviet/Russian space station over a period of 10 years, from 1988 to 1999. Later on, many astronauts have been using As de Coeur device during spaceflights, among them several Frenchmen/woman: JL Chretien, 26 days in 1988, M Tognini, 15 days in 1992, JP Haigneré, 21 days in 1993 and C André Deshays, 15 days in 1996.

And Now Retired


Now after retirement, what are your main activities? You told me some time ago that you are very busy giving different seminars all over France. I know also that you spend lots of time with the Planiol foundation. What can you tell us about the foundation?


In 2003 with Therese Planiol we decided to create a research foundation in neurosciences with three main objectives: funding research laboratories, funding mobility of young researchers, young researcher’s awards. The Planiol foundation www.fondation-planiol.fr was definitely founded in 2004. More than one million euros has already been attributed to researchers in neurosciences.


Being among the first professors who developed Doppler ultrasound and general ultrasound imaging, you must have received many prizes, awards and decorations during your career. Are there some you can list to us?


I was appointed Officer of the French Honorary Legion and received the National Order of Merit and the Academic Palms. I was also an Honorary member of Christian Doppler Academy, American Institute of ultrasound International, Academy of Astronautics, International Academy for Med. and Biol. Engineering.

I also participated to many IEEE Ultrasonics Symposium through which I received the IEEE Judith Resnik Award in 1995 and the Yan Donald Award for Technical Developments in 2003.


I think we are at the end of our discussion, do you want to add anything?


Thank you and to Jean Philippe and Jean Marc for carrying out the interview.


Thank you for welcoming us in your home and for your time.