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Dr. Mike

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  1. Like
    Dr. Mike reacted to Flaviu in Comparing FDM multi material options: Prusa MMU2 and Palette 2+   
    First of all, a lot of people in the "professional world" are using Ultimakers. And the Palette 2 is still not working with 2.85 filaments (and probably never will?)
    The last few months I came across a new scenario for multi material printing. It is mixing PLA with PETG for supports. PLA and PETG don't bond to each other. So you can print your part with PLA and supports with PETG (or vice versa) and set the contact z distance to 0(!). It works very well. Supports are coming off easy and the interface layers look as good as if you were using soluble supports. Since you have to keep soluble filament in dry conditions it is much easier (and cheaper) to use PETG instead. 
    Setting up the Palette is very easy. Mosaic has some videos one can watch like this one https://www.youtube.com/watch?v=uqbMw_M07GM (and the two follow up ones).
    As for my experience. The combination Prusa MK3 + Palette 2 is probably one of the most used one in the community and works very reliable (of course there is no 100% guarantee but lets say 98,5% of the time 😉) . And I always use and recommend Prusas. 
    Also I would recommend using this post processing tool for PrusaSlicer 2.0: https://github.com/tomvandeneede/p2pp for an Prusa+Palette combination. 
    I would also still strongly recommend the already mentioned DIY canvas hub guide. There is already an Octoprint beta version out for the new Raspberry 4 so chances are the guide might work with the new Raspberry 4. But I haven't tested it.
  2. Like
    Dr. Mike reacted to valchanov in 3D Printing My Skull   

    I'll try to walk you through this:
    1. First of all, install a proper dicom viewer. You can install Radiant for free and activate it with trial license, which you can renew unlimited times.
    2. Open the program, drag and drop the whole DICOM set and observe the series. There is a good volume rendering, multiplanar reconstruction and all the measurement tools you can possibly want. So, choose the series, which suits you best - probably the one with the thinnest slides.
    3. Check for pictures in the series, which are not supposed to be there. Sometimes some lazy radiologists are exporting the histiogram directly in the series, which disturbs the sequence algorithm of the medical informatics program, which you'll use later.
    4. Export the set - export-"current series"-"dicom". Choose a folder and hit "export".
    5. Load the set in 3D Slicer and use dr. Mike's basic tutorial. It's still one of the best tutorials. I myself prefer the segmentation editor module, but the basic editor is still a powerful tool. Make sure to remove "single file", when you're loading the set!
    6. If the CT scan is with 2mm thickness or better, you'll have your skull in no time, ready for 3d printing.

    I hope this will help. Thumbs up.
  3. Like
    Dr. Mike reacted to valchanov in Entry/Minimal Use 3d Printer recommendation?   
    If you want to scan people for fun, you can  use your cell phone for photogrammetry with free software. Then you can put the heads on different bodies and to print them. Something like this:

    For this purpose you can use every 3d printer up to 2000$. I myself prefer my original Prusa MK3, because I'm not an engineer and I prefer something to do all the printing stuff for me. Here is the result:

    When we're talking about medical 3d printing, we're talking about a whole different topic. The medical models have to be very precise and there is an industrial standards about it. For example, my models have 0,5mm deviation from the original body part at 95% confidence interval. I had a presentation at an morphology symposium about my favorite Lusoria model lately and now I have a lot of orders from the local hospitals, because of the standard, which I can achieve. For medical modeling you have to be an expert in all the morphological specialties (Anatomy, Pathology, Radiology) with some serious clinical background. To reach this level, you need:
    1. Medical education.
    2. A lot of treated patients, most of which have to stay alive after your job. The death patients are literally skeletons in the closet.
    3. Some background in the basic dissection techniques, both the pathological and the anatomical ones.
    4. The surgery training is a plus.
    5. Some gaming experience or experience with CAD software. The computer games are like bodybuilding for the visual cortex.
    6. 1+ years of hard work, everyday modeling, studying, drawing, dissections, consultations with the experts in the field, a lot of tears and some joy.
    THEN you can do medical modeling, something like this.
    I started to model, when I was an anatomy assistant professor, with 12 years of experience as an emergency internal physician. I had the chance to find this website with all it resources, tutorials and the awesome support from the administrators and after 1 year of really hard work, I became a professional, (one of the best in my region, in a matter of fact). But still, my biggest nightmare is that, because of my mistakes during the preoperative modeling, a patient will die. So - are we really talking about medical modeling or you just want to do some fun with your client's CT scans?
  4. Like
    Dr. Mike reacted to valchanov in Postprocessing 3D prints   
  5. Like
    Dr. Mike reacted to Flaviu in Comparing FDM multi material options: Prusa MMU2 and Palette 2+   
    You could use your Prusa printer with the palette 2. Their software has improved a lot the last few months and it should be a plug and play experience now.
  6. Like
    Dr. Mike reacted to Flaviu in 3D printing white matter tracts in the brain. MR tractography   
    If you want FDM printing with many colors you should consider the da Vinci Color from XYZ printing (https://www.xyzprinting.com/de-DE/product/da-vinci-color). 
    The print quality is OK for an FDM printer. They are also not very reliable (compared to something like a Prusa MK3).
    But you can print with many colors and they lowered the prizes a bit.
  7. Like
    Dr. Mike got a reaction from jaime rosario nieves in Lots of interest in 3D printing from Ultrasound   
    There seems to be lots of interest in this community regarding 3D printing from ultrasound images. Does anybody know of resources available to show how to do it? I'm sure many here would be interested.
  8. Like
    Dr. Mike got a reaction from KalN in Why is download limit applied to paid items as well?!   
    Agreed. This limit was put in place to prevent abuse for free downloads, but should not apply to paid items. We are working on a fix. You should now be able to download your files. Thank you for letting us know about this issue.  
  9. Like
    Dr. Mike reacted to kopachini in Skull is seen as two shells   
    Dear olatif2 when in blender, choose edge select and then ALT + LMB/RMB (depending your preferences) and it should select whole edge (tabula externa) than try SHIFT+ALT+LMB/RMB  and select tabula externa and than when both edges are selected pres F and sgould get a facet (closed gap).
    Or faster way would be to add a new object (cube), size it up, put it below both edges and boolean operation difference and should get closed edges of the skull but slightly lower model than it would be at first.
  10. Like
    Dr. Mike got a reaction from kopachini in Multimaterial skull model of MCA aneurysm to practice neurosurgical clipping   
    We recently 3D printed a multimaterial skull with MCA aneurysm from a CTA head for customer who needed the skull in rigid plastic and the vessels and aneurysm in flexible material. The model will be used by neurosurgeons to practice intracranial aneurysm clipping surgery. To properly simulate the surgery, the skull needs to be hard and the vessels elastic. Combining two materials (and two printers!) provides the best solution. The model was created on democratiz3D. You can learn more about embodi3D's printing service here. 

  11. Like
    Dr. Mike got a reaction from ramon in Holes in bone models with democratiz3D   
    I'd like to elaborate on this topic a bit, as I recently had another member inquire about this issue. The member was creating a model from a CT scan of the clavicles. As you can see, there are holes in the medial (midline) ends of both clavicles. What is causing this? Is it a problem with democratiz3D? How can it be fixed?

    The issue lies with the patient's anatomy and the quality of the original CT scan. In the human body there are areas where bones are naturally very thin. Sometimes, the bone surface (cortex) can be  paper thin. Also, some patients who have conditions like osteoporosis may have very little calcium in their bones. Issues like this make it very hard for the CT scanner to detect the bone wall, as you can see from the image below which shows the area on the left clavicle that has a hole in the final model (red arrow). The problem isn't with democratiz3D, but with the quality of the CT scan or with the patient having thin bones (how dare they!).  democratiz3D is actually creating the model exactly as it appears on the CT, its just that the CT has holes we don't want!

    So, what can be done? If you encounter this problem you have two options. 1) Manually fix the holes in the model with a mesh editor like Meshmixer, or 2) decrease the threshold value in democratiz3D and re-process the scan. Decreasing the threshold tells the system to capture more voxels in your model, potentially capturing more thin or osteoporotic bone. But, be careful. If you reduce the threshold too much (less than 100), you run the risk of starting to capture muscle, organs, and vessels in your bone model. If you are not sure what threshold to use, you can experiment by running your scan through democratiz3D using different thresholds. To save time, I suggest you do this on low or medium quality setting. When you find a threshold that works, you can generate your final model using a higher (and more time consuming) quality setting, like High or Ultra.
    If you are familiar with mesh editing software, that is probably the fastest way to correct this problem. Just delete the edge of the hole, fill it in with a new face, and run a quick smooth operation on the area. It's a 1 minute fix if you know the keyboard shortcuts.

    I hope this tip helps.

    Dr. Mike

  12. Like
    Dr. Mike got a reaction from ramon in Holes in bone models with democratiz3D   
    I received this inquiry from a member. I am going to post the response here so that it can help others with the same question:

    QUESTION: "I am printing out a spine model....  Why are there so many defects in the rendering?  I can't print this out on a 3d printer, half of the vertebrae are hollow.  I get these from a 3d CT and on a computer monitor, the vertebrae are whole.  Just take a look at the thumbnails and you'll know what I'm talking about.  I don't have the expertise or time to fill all of the defects.  Is there a paid service somewhere that could do this for me?  I'm just surprised the STL file wouldn't look like the 3d CT since they use the same dicom imagery?"

    ANSWER: If you are creating bony models and are finding that the bones have holes or other large defects in them (see above), this is probably an issue with the Threshold value used during the conversion. Threshold is the number of Hounsfield units to use to create the surface of the model. Anything above the threshold value is considered bone and is included. Anything below is not considered bone and is excluded. Normal cortical bone is very dense, greater than 300 Hounsfield units, so the default threshold of 150 is more than enough to catch it. The inside of the bone (medullary, or marrow cavity) is filled with fatty bone marrow and is a much lower Hounsfield value. If the patient has osteoporosis or very thin cortical bones they may not register as bone if the default threshold of 150 is used. You can decrease this to a lower threshold value (maybe 100 or so) and you will be more likely to capture this thin, deossified bone. If you go too low though (60 or so) you will start to capture non-bony structures like muscle. 

    Another thing that may help get the highest quality models is using premium operations such as Very Detailed Bone and Ultra quality level. These operations are time-consuming however. To save on time, you can run your scan through democratiz3D using free operations such as Detailed Bone and medium or high quality until you find the threshold you like. Once you find the threshold value you like, you can run you scan through a final time using the highest quality (and slowest) operation settings, such as Very Detailed Bone and Ultra quality.
    Hope this helps!
    Dr. Mike
  13. Thanks
    Dr. Mike reacted to Josip Rauker in 3D printing cranial and craniofacial implants   
    I am a biomedical engineer, I own a CAD/3D print Company in Croatia. My Company is specialized in production of 3D printed moulds for making patient specific cranial implants out of PMMA. This is a rather cost effective way to produce patient specific cranial impants. I use Solidworks for designing implants and moulds. This software isn´t free, but it's cheaper than Geomagic.
    The whole procedure is described in an article I have published on my LinkedIn page:
  14. Like
    Dr. Mike reacted to QPRINT3R in Dr. Mike Presenting at Mayo 3D Printing Conference Feb 23 -25 2018   
    Hi Mike, Is there a Mayo Clinic Collaborative 3D Printing in Medical Practice 2019? I can't seem to find any current information on it?
  15. Like
    Dr. Mike reacted to rishabhjaiswal in image extraction   
    Hello, I want to extract the geometry fro angiographic data ....please tell me......it is an aneurysm ...cerebral.....I Have data with me ....which is in angiographic formate
  16. Like
    Dr. Mike reacted to kopachini in image extraction   
    you have several tutorial videos on this web page how to segment a model. but instead of bones which are in the video, you choose contrast blood to segment.
  17. Like
    Dr. Mike reacted to QPRINT3R in Printing vasculature nerves and delicate organic parts   
    Hi everyone,
    I have been printing for a long time with my Ultimaker 2+. As a result I am limited when it comes to creating detailed models that have extensive organic shapes like branching vessels etc... There is only so much supports and laborious cleanup can do. I have not been able to test the Ultimaker S5 with the addition of dissolvable materials. Knowing what I am after would you recommend skipping FDM printing and looking at the Form2? Are there Pros and Cons that apply to medical or organic model printing beyond build volume that would be valuable when considering what direction to go?
    Lastly, I realize that it can be difficult to calculate cost, but what overall expenses would one expect to see from the same part printed by FDM vs SLA?
    Any help, suggestions or advice would be greatly appreciated.
  18. Like
    Dr. Mike reacted to los in Looking for DICOM files   
    New Mexico is working on getting a CT database up and running some time in 2019. Below is recent link
  19. Like
    Dr. Mike reacted to Piotr Zielinski in 3D printing cranial and craniofacial implants   
    I am a neurosurgeon. The simplest way to solve most of our problems in a low cost and rather according to the rules way is to first to print the patients skull (easy). Than to form manually, slowly and exactly a lacking bone from the cheap, available everywhere in the world dental molds (I have succeeded with silicone prosthetic mold). When the bone substitute is ready and firm, then make an impress in a stomatologic  acrylic mass (methacrylate, the ubiquitous surgical material), also available everywhere. Its the same component that we use to form a bone in the operating theatre, but not sterile. If you have the mold ready, you can sterilise it in a plasma autoclave, put in a sterile foil bag in the operating theatre and then form in this foil and form a lacking skull piece from a classic methacrylate. Sterile, with all of the certificates needed. It does work.
    Ready 3D printed skull flaps are often imperfect. I.e. they do not take into consideration brain swelling, soft tissue remodelling etc. The mold and forming the bone flap during surgery from PMMA seems to be much more versatile. And you do not have to throw away the bone substitute of 2000 USD into trash.
    Best regards,
  20. Like
    Dr. Mike reacted to Flaviu in Comparing FDM multi material options: Prusa MMU2 and Palette 2+   
    Dear all,
    I'd like to add something to my original post. I advised to buy the canvas hub. Don't do it!
    It's just a Raspberry Pi Zero W with Octoprint on it. Instad you should buy a Raspberry Pi 3 B+ (or newer) and install Octoprint yourself on it. Setup guide at: Canvas Octoprint Guide.
    The whole system will work with less lags because the Zero W is a lot slower than the 3B+ and you will save some money  
    Regarding Printing time.
    When you have the possibility to purge into infill (available with Prusa system and in the near future with the Palette 2) the purge block will shrink if you print bigger parts (more infill).
    The lumbar spine I've printed is cut through the middle and I've printed both parts at once:
    No supports 30% infill 3 perimeters 0.15 layer hight (0.4 nozzle) Total print time 44 hours on my Prusa MMU2. (around 270 color changes) (Palette 2 should be about the same time.) Total print time as a single color print would be 38 hours. Soluble supports.
    I print all my (interface) supports with Verbatim BVOH. It works great with PLA but ...
    Maximum printing speed is around 20 mm/s (so way slower than PLA) You have to purge a lot (at least 120 mm^3 on every change which is about double the amount for a normal color change and it should be even more with the Palette 2) You have to use a container with low humidity and sometimes dry it.   
    Palette 2 with dual extruder.
    It doesn't work atm. Since it is a very closed system it should be extremely difficult if not impossible for some one from the community to add this feature. If the company behind the product is working on this I don't know. 
  21. Like
    Dr. Mike reacted to Flaviu in Research paper: Guidelines for medical 3D printing   
    The RSNA/SIG released a paper about guidelines for medical 3d printing.
    Download link e.g.: Radiological Society of North America (RSNA) 3D printing Special Interest Group (SIG): guidelines for medical 3D printing and appropriateness for clinical scenarios
    On page 7 there is an interesting table with ratings from 1-9 about the usefulness of 3d printing on specific medical scenarios:
    1-3: rarely appropriate
    4-6: maybe appropriate
    7-9: usually appropriate
  22. Like
    Dr. Mike reacted to valchanov in Formlabs Fuse 1 SLS printer   
    There is a game changer on the SLA front - Josef Prusa made an open source SLA printer - Prusa SL1.  You can buy two of those and one Prusa MK3 with the money for one Form 2. It prints down to 10 microns layer thickness (after some tweaking of the slicer). It is open source, which means that the wave of cheap prusa clones is coming. This will change the whole SLA sector because let's face it - with the money for one Form 2 you can buy a whole 3D printer farm with the best printer of Winter 2018 (Prusa MK3) or you can buy two printers of the same class, with the same parameters, which requires more tinkering and experienced staff.  The bad side about the Prusa printers are the limited Wi Fi options...
  23. Like
    Dr. Mike reacted to Flaviu in Formlabs Fuse 1 SLS printer   
    I'd like to warn everyone from using Prusas SLA or other cheap (Chinese) SLA printers instead of a Form 2.
    The Form 2 has a cartridge system for the resin. The cheaper SLA printers don't have that so you are a lot more "in contact" with the resin. This makes the whole process a lot more difficult/complex and might even be harmful to your health. 😐
  24. Like
    Dr. Mike reacted to madjid_hatefi in Converting Ultrasound Files   
    Hi guys
    Does anybody know how to convert MVL. files (Fetus 3d ultrasound file) to DICOM or NRRD in order to making 3d model?
  25. Like
    Dr. Mike reacted to kopachini in Converting Ultrasound Files   
    I found in the 3D Slicer forum this topic that may help you. There is software called TomoVision that could help you, but you must buy it.
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