What type of incubation conditions are provided?
EmbryoScope is a benchtop style tri-gas incubator. Continuous recycling of the internal gas volume through filters removes potentially harmful VOC and particles. Internal carbon dioxide concentration is measured with a high-quality IR sensor and the oxygen with an amperometric sensor. Oxygen and carbon dioxide concentrations are regulated by mixing CO2 and N2 into the internal airstream (it is not possible to use pre-mixed gas). The tri-gas mixer ensures a stable gas composition and a low consumption. Proportional gas regulation ensures a fast response to openings of the load door so incubation conditions are rapidly restored (<5 min for CO2 and <15 min for O2 regulation). Direct thermal contact between the EmbryoSlide and the slide holder ensures that the temperature is stable and virtually unperturbed in situations of load door openings. All told, this results in stable incubation conditions with clean controlled gas and a constant temperature for the entire incubation period.
How many focal planes are acquired?
Images of each embryo are acquired in 1, 3, 5, 7 or 9 equidistant focal planes. In general, most clinics acquire time-lapse videos of embryo development in 7 focal planes. The distance between the focal planes can be changed as required by the user in the software.
What is the frequency of image acquisition?
Acquisition of images in 7 focal planes of 72 embryos is acquired approximately every 10 minutes.
How is air quality and contamination controlled?
Internal circulation of the air inside the EmbryoScope™ passed through a volatile organic compound (VOC) filter, a high-efficiency particulate air (HEPA) filter. An ozone-free 254 nm UV-light illumination lamp (EU only) further ensures a purified and clean air supply. The total air volume is approximately 20 L (the incubation area 3 L) and the flow rate is >120 L/hr, so all air passes through the cleaning filters several times an hour. The UV illumination kills any microorganisms attached to airborne particles in the gas stream and the HEPA VOC filter retains them.
Why use a non-humid environment?
The risk of fungal and bacterial contamination is greatly reduced in a non-humid environment. The EmbryoSlide culture dish are not permeable to water vapour. Covering culture medium droplets with an oil film a humid environment unnecessary as evaporation is barely detectable (< 1% of volume per day). There is no need to replenish water reservoirs and accidental condensation of water vapour within the instrument is eliminated (see abstract from ASRM 2011, 96(3) Suppl, Okimura et al ”Efficiency of dry culture system in human blastocyst culture”).
How was safety of light exposure to the embryo tested?
The total embryo light exposure has been measured with a light microsensor and was found to be substantially lower than in conventional IVF procedures with normal microscopes. Total exposure time in the EmbryoScope time-lapse system over three days of culture and acquisition of 3024 images is 136s which compares favorably with the 167s microscope light exposure reported for a standard IVF treatment (Ottosen et al 2007). (see technote; Exposure to light during image acquisition in the EmbryoScope™ time-lapse system). When evaluating embryonic light exposure in IVF, it is essential to use a scalar irradiance microsensor with the same dimensions as an embryo. A scalar irradiance microsensor is a tapered optical fibre with a light-diffusion sphere at the tip, so that incident light from all angles is measured - including reflected light. Only by using a microsensor with the same dimensions and shape as an embryo and placed in the embryo’s position, is it possible to obtain a true recording of the incident light hitting the embryo in different experimental setups. Furthermore, the spectral composition of the light in the EmbryoScope™ was confined to a narrow range and thus devoid of low wavelength light below 550 nm, which has been shown to be inhibitory for embryo development (Takenaka et al 2007; Oh et al 2007) and makes up about 15% of the light encountered in a normal IVF microscope. The discrete wavelength provided by the LED means that the wide spectral composition of light used in a standard microscope, including damaging light shorter than 550nm, is totally eliminated.
What imaging system is used in the EmbryoScope time-lapse incubator?
The imaging system in the EmbryoScope incubator uses internal optics which are very light-sensitive and designed to work with illumination from a single red LED providing light at 635nm. The optics use modified Hoffmann modulation contrast with a 20x speciality Leica objective to provide optimal light sensitivity and image resolution using the red wavelength.
What kind of culture dish is used?
The EmbryoSlide culture dish is a CE-marked Type IIa Medical Device and FDA-cleared 510k for human clinical use. It is composed of medical grade polystyrene and tested by exactly the same tests as other IVF-approved culture dishes. All production lots are QC-tested by external companies according to approved practices for: i) Sterility (ISO11137 with SAL 10-6), ii) Cytotoxicity (USP method <87> and ISO 10993-5); iii) Non-pyrogenic (< 20 Endotoxin units/device) and iv) Embryo toxicity (tested with mouse zygote development to fully expanded blastocysts over 96 hrs; the acceptance criterion is ≥80% expanded blastocysts). A certificate to this effect is included with all shipments of the EmbryoSlide culture dish.