PTI250 – 3D measurement of hip and intervertebral disc implants

Implant production is very elaborate and is terminated by a complex traditional measuring method. Manufacturers of implants accept the need to purchase several expensive 3D measuring instruments which are located separately from production in the precision measurement room, and sometimes after the measurement leave traces on the precisely processed surfaces. At the same time and for more than 30 years, the optical industry makes use of a very simple, non-contact and highly accurate method to determine the radius of the surface area of a sphere. In laser interferometry, the surface form is acquired during the first measurement.

The sample is in the so-called confocal position which in case of the sphere surface is precisely in the spherical wavefront. The second position is in the focal point of optics and is also called cat‘s eye position. The implant radius results from the determination of the geometric distance between confocal position and cat’s eye position. This distance measurement is made on the optical axis either by means of a glass ruler or an additional laser interferometer. The entire measuring procedure is based on certified sphere standards.

ZYGO PTI250

The ZYGO PTI250 offers access to automatic radius measurement. The compact Fizeau interferometer is mounted on a motorized z-stage with encoder. As in the case of each Fizeau interferometer, the objective lenses with different focal lengths can be exchanged very quickly and easily. The adaptation of the measuring sensors to the implant radius is made without recalibration or time-consuming adjustment. Our VeriFire in the MetroCell workstation is offered for the use with large implants. Its sample stage is also movable along the x-axis and/or the y-axis. The complete motorization makes an even higher degree of automation possible. As an additional advantage, both systems can be integrated directly in production.

Exemplary measurement

The two measurements show the pairing of a hip implant. Both the femoral head and the acetabulum are shown in 3D view. The deviation from the spherical form is visible. The specified Pt-value is only one of many results that have to be calculated. The measurement was made with a PTI 250 and in this configuration covered a sphere surface of 55%. Objective lenses which cover a bigger surface area are also available. The measuring time is approximately 10 seconds. More ZYGO products will be presented on the occasion of the international trade fair Control in Stuttgart.

Code 752: Information on the PTI250

Open new Spectrum Code Card (if you don't have one opened already)

info@zygolot.de

↑ Back to Top ↑

International:

Szukaj:



→ Alphabetical Search Index → Sitemap

Linki:


Quantum Design:
→	www.qd-international.com

Nowości:


→	Spectrum European Edition 11 (June 10) is online!
→	Anasys Instruments: Nanoscale IR spectroscopy and thermal analysis
→	SPM insert for the QD PPMS®


	LOT-Oriel Polska E-mail: kowalczyk@lot-oriel.pl				Szyb Walenty 32 41-700 RUDA SLASKA, POLEN				Phone/Fax: 48 322482048		emotiv design