A Nobel chain of development

In research being conducted by PhD student Jan Heemskerk, a  method for medical imaging uses a pin-holes technique (bottom image) supported by CCD cameras that allows for much sharper images of the human organs being examined for tumours and other medical maladies. The new pin-hole technique is a vast improvement on the currently used collimation (top image) method. (Illustration: Jan Heemskerk)

This year’s Nobel Prize of Physics has been awarded to Willard S. Boyle and George E. Smith for their invention of the CCD sensor, and to Charles Kao for his scientific achievements regarding the transmission of light in optical fibres. Both of these inventions now belong to everyday life – CCD sensors for instance feature in digital cameras – and of course CCD sensors and optical fibres also figure prominently in various TU Delft research projects.
Jan Heemskerk, a PhD student from TU Delft’s Radiation, Detection and Medical Imaging section, is working on a setup with CCD sensors. The aim is to build a new type of gamma-ray detector for medical applications.
‘When a gamma-ray picture is taken of a human body, we usually need a detector as large as the body itself, because gamma-rays are difficult to bend,” Heemskerk says. “We’re now developing a method to reduce the size of the detector.”

Heemskerk explains that, with this new method, “first small amounts of radioactive material are brought inside the patient’s body, which is done by attaching the material to a biological molecule – or tracer molecule – that seeks a tumour, for example.”
In Heemskerk’s method, radiation emitted by radioactive elements is captured by a pinhole – a small hole like in a camera obscura: “A CCD sensor is placed behind this pinhole and captures the final image,” he says, adding that this new type of detector is smaller than those currently used. “The radiation coming from the radioactive material emits in all directions; therefore one small CCD camera can make an image of large parts of the body, such as the brain.”

Another advantage of this setup is that the amount of radiation needed is smaller, which of course benefits the patient. The medical application of CCD in Heemskerk’s setup is no exception.
Professor Freek Beekman, head of the Radiation Detection and Medical Imaging section, says that in recent years the CCD camera is increasingly being applied in medical applications, such as with endoscopy: “The CCD sensors used for our medical research make a thousand times less noise than the one in your photo camera.” Consequently, CCD sensors are also now used by the military for night-vision equipment.

Perspective
The CCD sensor, as invented by Nobel Prize winners Boyle and Smith, was not originally developed with this application in mind; rather, the two scientists had only planned to use the sensor as electronic memory, not as cameras capable of detecting single photons.
Dr Florian Bociort, of the Imaging Science and Technology section, puts the idea that Boyle, Smith and Kao are the inventors of CCD and optical fibres into perspective: “Apart from Nobel Prize Laureates, many other researchers have contributed to achieving the quality of CCD sensors and optical fibres as we know them today. The Laureates are considered to have contributed an important part to the chain of developments.”
He takes the development of optical fibres as an example: ‘For optical fibres, it was thought that they were impractical, because of the large attenuation of the signal as it travelled through the fibre. However, Kao discovered that by using improved glass quality this problem could be solved.”

The optics group at TU Delft’s faculty of Applied Sciences claims that one of the faculty’s former professors, Bram van Heel (1899-1966), made an essential contribution in the early stages of fibre optics. “He published an article entitled ‘A new method for transporting optical images without aberrations’ in Nature in 1954,” Bociort says. “But when looking at the history of optical fibres he usually isn’t mentioned.”
Nevertheless, credited or not, Van Heel certainly contributed to the chain of inventions leading to the optical fibres of today. How much further this chain of invention will stretch, no one can ever say.

The New American University. De titel van Michael Crows inaugurele rede liet geen enkele twijfel bestaan over de ambities van de bestuursvoorzitter van Arizona State University (ASU). Bij zijn aantreden in 2002 stelde Crow zich ten doel ASU om te vormen tot de nieuwe gouden standaard van het Amerikaanse onderwijssysteem. Dat systeem is volgens Crow hard aan vernieuwing toe, als het op een zinvolle manier wil bijdragen aan de brede maatschappelijke vraagstukken van deze tijd. Topuniversiteiten als Harvard, Yale, MIT en Princeton staan in zijn ogen symbool voor een verouderd model dat zich kenmerkt door zijn kachelpijpstructuur: de wetenschappelijke disciplines zijn gevangen in hun eigen nauwe probleemdefinities die alleen maar kunnen leiden tot gedeeltelijke oplossingen, terwijl de werkelijke, grensoverschrijdende uitdagingen onaangeroerd blijven. De nieuwe Amerikaanse universiteit daarentegen staat midden in de samenleving en neemt met probleemgestuurd onderzoek het voortouw in lokale en globale duurzaamheidkwesties.
Het bleef niet bij mooie woorden alleen. In zijn strijd tegen de academische verzuiling gooide Crow de hele blokkendoos van faculteiten en afdelingen overhoop en begon opnieuw te bouwen. Hij verving 20 van de 23 decanen, schafte diverse afdelingen af en richtte interdisciplinaire onderzoekscentra op zoals het Biodesign Institute, het Global Institute of Sustainability, en de School of Earth and Space Exploration, waar wetenschappers van diverse pluimage aan probleemgestuurde onderzoeksprojecten werken. ‘Intellectuele fusie’ is daarbij het sleutelwoord: onderzoekers kijken voorbij de grenzen van hun eigen disciplines en proberen gezamenlijke oplossingen te formuleren voor maatschappelijke vraagstukken. Zo werken microbiologen, procesingenieurs en sociale wetenschappers in het project Tubes in the Desert samen aan de productie van biobrandstoffen uit zonne-energie met behulp van blauwalgen.
Niet iedereen is even blij met de dadendrang van de voorzitter. Critici menen dat de bemoeizucht van Crow de universiteit uiteindelijk zal opbreken. Studenten klagen over de fors toegenomen studiekosten. Hoogleraren voelen zich onbegrepen, spreken over oude wijn in nieuwe zakken. Maar vooralsnog stijgen zowel de studentenaantallen als het aanzien van de universiteit in rap tempo. ASU is de jongste universiteit in de top 100 research/universities van de Carnegie Corporation, sponsors staan in de rij om onderzoeksprojecten te financieren en rondom de campus schieten nieuwe universiteitsgebouwen als paddenstoelen uit de grond. Zeven jaar na zijn aantreden is Crow een heel eind op weg met de verwezenlijking van zijn droom.
De succesvolle ondernemer die in een paar jaar tijd in zijn eentje een imperium uit de grond weet te stampen: Amerikaanser kan het niet. Toch zouden delen van het succesverhaal van Crow ook op universiteiten in andere culturen van toepassing kunnen zijn. Dat wetenschappelijke kwaliteit en maatschappelijke relevantie elkaar niet hoeven te bijten bijvoorbeeld. Dat interdisciplinair onderzoek tot onverwachte inzichten kan leiden. En vooral: dat breken met oude tradities vitaliserend kan werken. Misschien kunnen de ideeën van academische ontzuiling en interdisciplinariteit ook een frisse wind in de Hollandse polder laten waaien. Wie weet: misschien staat de nieuwe Nederlandse universiteit straks wel in Delft.

Dit is het tweede deel van een drieluik over het leven aan de Arizona State University.

Drs. Daan Schuurbiers is onderzoeker bij de werkgroep biotechnologie en maatschappij.

In research being conducted by PhD student Jan Heemskerk, a  method for medical imaging uses a pin-holes technique (bottom image) supported by CCD cameras that allows for much sharper images of the human organs being examined for tumours and other medical maladies. The new pin-hole technique is a vast improvement on the currently used collimation (top image) method.
(Illustration: Jan Heemskerk)

This year’s Nobel Prize of Physics has been awarded to Willard S. Boyle and George E. Smith for their invention of the CCD sensor, and to Charles Kao for his scientific achievements regarding the transmission of light in optical fibres. Both of these inventions now belong to everyday life – CCD sensors for instance feature in digital cameras – and of course CCD sensors and optical fibres also figure prominently in various TU Delft research projects.
Jan Heemskerk, a PhD student from TU Delft’s Radiation, Detection and Medical Imaging section, is working on a setup with CCD sensors. The aim is to build a new type of gamma-ray detector for medical applications.
‘When a gamma-ray picture is taken of a human body, we usually need a detector as large as the body itself, because gamma-rays are difficult to bend,” Heemskerk says. “We’re now developing a method to reduce the size of the detector.”

Heemskerk explains that, with this new method, “first small amounts of radioactive material are brought inside the patient’s body, which is done by attaching the material to a biological molecule – or tracer molecule – that seeks a tumour, for example.”
In Heemskerk’s method, radiation emitted by radioactive elements is captured by a pinhole – a small hole like in a camera obscura: “A CCD sensor is placed behind this pinhole and captures the final image,” he says, adding that this new type of detector is smaller than those currently used. “The radiation coming from the radioactive material emits in all directions; therefore one small CCD camera can make an image of large parts of the body, such as the brain.”

Another advantage of this setup is that the amount of radiation needed is smaller, which of course benefits the patient. The medical application of CCD in Heemskerk’s setup is no exception.
Professor Freek Beekman, head of the Radiation Detection and Medical Imaging section, says that in recent years the CCD camera is increasingly being applied in medical applications, such as with endoscopy: “The CCD sensors used for our medical research make a thousand times less noise than the one in your photo camera.” Consequently, CCD sensors are also now used by the military for night-vision equipment.

Perspective
The CCD sensor, as invented by Nobel Prize winners Boyle and Smith, was not originally developed with this application in mind; rather, the two scientists had only planned to use the sensor as electronic memory, not as cameras capable of detecting single photons.
Dr Florian Bociort, of the Imaging Science and Technology section, puts the idea that Boyle, Smith and Kao are the inventors of CCD and optical fibres into perspective: “Apart from Nobel Prize Laureates, many other researchers have contributed to achieving the quality of CCD sensors and optical fibres as we know them today. The Laureates are considered to have contributed an important part to the chain of developments.”
He takes the development of optical fibres as an example: ‘For optical fibres, it was thought that they were impractical, because of the large attenuation of the signal as it travelled through the fibre. However, Kao discovered that by using improved glass quality this problem could be solved.”

The optics group at TU Delft’s faculty of Applied Sciences claims that one of the faculty’s former professors, Bram van Heel (1899-1966), made an essential contribution in the early stages of fibre optics. “He published an article entitled ‘A new method for transporting optical images without aberrations’ in Nature in 1954,” Bociort says. “But when looking at the history of optical fibres he usually isn’t mentioned.”
Nevertheless, credited or not, Van Heel certainly contributed to the chain of inventions leading to the optical fibres of today. How much further this chain of invention will stretch, no one can ever say.