[IGSTK-Developers] Does IGSTK need any calibration components?

[Hui Zhang]

Hi, David,

That pivot calibration class takes the inputs from the tracker, (translation 
and orientation), as many samples as the user wants, and then calculates the 
3D translation from the sensor/marker to pointer's tip. And also it will 
return the RMS error in the computation. I used it for tracked needle 
calibration, which has only one offset along z-axis, but I can extend it to 
3D translation for optical and other trackers by adding two more variabels.

The ultrasound calibration class is a general 2D/3D imaging to tracker 
calibration. The inputs are:
1. the point index in 2D/3D imaging space;
2. the concurrent reading from 6DOF tracker;
3. the point coordinate in the tracking space;
It will need at least 3 or more frames to compute the matrix.

One question is, these two classes use Vnl functions through ITK, so will it 
affect the current IGSTK structure? It uses vnl to perform some matrix 
operations.

The mathematic part is in our EMBS and SPIE papers, and we use the simple 
matrix operations. I can attach it if IGSTK needs.

If the requirement and the mathematica part are approved, I can try to begin 
put it into sandbox.

Regards
James

----- Original Message ----- 
From: "David Gobbi" <dgobbi at atamai.com>
To: "Hui Zhang" <zhang at isis.imac.georgetown.edu>
Cc: "'IGSTK-developers'" <igstk-developers at public.kitware.com>
Sent: Wednesday, November 16, 2005 12:09 PM
Subject: Re: [IGSTK-Developers] Does IGSTK need any calibration components?


> Hi James,
>
> Yes, IGSTK will need a pointer calibration component, so if you can
> supply one then that would be great. Also, any description of the method
> would be useful - it is very important that all of the mathematical
> algorithms used by IGSTK are well documented.
>
> For ultrasound, we will probably want to wait until we have a video
> acquisition class for IGSTK. The crossed-wire method is a good
> calibration method to support. There are tons of different ultrasound
> calibration methods, but the crossed-wire method is as accurate as any
> of the others, and the phantom is easy to construct.
>
> - David
>
> Hui Zhang wrote:
>
>> Hi, all,
>>
>> Does IGSTK need any calibration components, like track tool
>> calibration and ultrasound probe calibration?
>>
>> One important part of current IGSTK is the tracker component. When we
>> use tracker tools, those tools must be calibrated using pivot method
>> to calculate the transform from sensor/marker to the hot point (tip or
>> something else). Normally this step is done by using the software from
>> the company like NDI ... But sometime it is important to have the
>> ability to do the on-site calibration. As I know, one of Philips
>> software integrates this function in their navigation system. We have
>> developed one class here to calculate the transform through those
>> pivot samples. If IGSTK needs this component, I can try to contribute
>> this part and make it state machine -able.
>>
>> Another component we have here is the point-based ultrasound probe
>> calibration class, which can handle the freehand ultrasound
>> calibration by using the pointer or some phantoms like cross-wire
>> phantom. This calibration component is essential to integrate
>> ultrasound ability to image guided system. It can be extented to
>> calibrate the general imaging device to trackers.
>>
>> Regards,
>>
>> ---------------------------------------------------------------------------------------------
>>
>> Hui (James) Zhang, Ph.D.
>>
>> Imaging Science and Information Systems (ISIS) Center
>> Department of Radiology
>> Georgetown University Medical Center
>> 2115 Wisconsin Avenue, Suite 603
>> Washington, DC, 20007
>>
>> Work phone: 202-687-2902
>> Work fax: 202-784-3479
>> Cell phone: 240-476-9361
>> MSN: zh_skyfox at hotmail.com
>> ----------------------------------------------------------------------------------------------
>>
>>
>>
>> _______________________________________________
>> IGSTK-Developers mailing list
>> IGSTK-Developers at public.kitware.com
>> http://public.kitware.com/cgi-bin/mailman/listinfo/igstk-developers
>>
>
>