TISSUE MARKING SYSTEM

Abstract

A marking system (10) includes a tissue holder (14) which has a cover (16). An inner surface of the cover (16) is coated with a donor layer (18). A pulsed laser (20) emits a laser pulse sufficient to transfer material from the donor layer (18) onto tissue (12) held in the tissue holder (14) by means of a laser-induced forward transfer (LIFT) technique, and the material transferred to the tissue (12) creates a mark on the tissue (12).

Claims

1. A marking system (10) comprising: a tissue holder (14) which has a cover (16), wherein an inner surface of said cover (16) is coated with a donor layer (18); and a pulsed laser (20) configured to emit a laser pulse sufficient to transfer material from said donor layer (18) onto tissue (12) held in said tissue holder (14) by means of a laser-induced forward transfer (LIFT) technique, said material transferred to the tissue (12) creating a mark on the tissue (12).

2. The marking system (10) according to claim 1, wherein said laser pulse is sufficient to vaporize material from said donor layer (18) and said material condenses on the tissue (12).

3. The marking system (10) according to claim 1, wherein said laser pulse is sufficient to transfer material from said donor layer (18) without vaporizing the material.

4. The marking system (10) according to claim 1, wherein said donor layer (18) comprises at least one of a visible or fluorescent ink, a paste, a polymer, a metal, a quantum dot and a nanoparticle.

5. The marking system (10) according to claim 1, wherein said pulsed laser (20) is configured to operate in a wavelength range of 100-700 nm with an energy fluence of 40-100 mJ/cm.sup.2 and pulse duration of 0.001-100 sec.

6. A method for marking comprising using said system of claim 1, comprising emitting a laser pulse sufficient to transfer material from said donor layer (18) onto the tissue (12) held in said tissue holder (14) by means of LIFT.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which:

[0015] FIG. 1 is a simplified illustration of a tissue marking system, constructed and operative in accordance with a non-limiting embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0016] Reference is now made to FIG. 1, which illustrates a tissue marking system 10, constructed and operative in accordance with a non-limiting embodiment of the present invention.

[0017] In one embodiment, a tissue sample 12 is held in a tissue holder 14 which has a transparent or translucent cover 16 (e.g., a glass cover). An example of a suitable tissue sample holder 14 is the CLEARPACK tissue holder, commercially available from ClearCut Medical Ltd., Israel. This tissue holder is constructed of MR inert materials and is transparent. In this embodiment, the CLEARPACK tissue holder is modified in that the inner surface of cover 16 is coated with a donor layer 18 for creating a location marker, which is transferred from the cover 16 onto the tissue 12 right after the imaging scan (such as an MRI scan; but the invention can be carried out with other imaging techniques, such as x-ray) before the tissue 12 is removed from the tissue holder 14. In one embodiment the mark is made with laser-induced forward transfer (LIFT) techniques.

[0018] LIFT is a direct-writing technique that allows depositing tiny amounts of material from a thin film (e.g., deposited onto a transparent holder) to a receptor substrate by means of a laser pulse. The technique was initially developed to transfer inorganic materials from precursor solid films. The laser pulse completely vaporizes a small portion of the solid film and the vapor condenses onto the receptor substrate as a marking (e.g., a solid dot). LIFT has also been developed to transfer materials that are in the form of a paste or liquid. Instead of being vaporized, a small volume of paste or liquid is directly ejected from the holder under the action of the laser pulse, and the material preserves its paste or liquid nature once deposited onto the receptor substrate

[0019] Accordingly, a pulsed laser 20 may emit a laser pulse to heat and evaporate the coating material (donor layer) 18, thereby transferring the coating material 18 from cover 16 and depositing transferred material 19 onto the tissue 12 at the precise location which is required to be marked. The tissue 12 may be in direct, mechanical contact with the donor layer 18. The gap shown in FIG. 1 is not necessarily required.

[0020] Materials suitable for printing include, without limitation, visible or fluorescent ink, pastes, polymers, metals, quantum dots, nanoparticles, or any other material that will evaporate from the tissue holder cover, whereupon the vapor will condense and adhere to the tissue (which is usually wet, but could also be dry) to create the desired mark, or pastes or liquids which can be transferred without evaporation.

[0021] Different lasers and pulse parameters may be used to carry out the invention. Without limitation, lasers in the wavelength range of 100-700 nm with an energy fluence of 40-100 mJ/cm.sup.2 and pulse duration in the range of 0.001-100 sec may be used.

[0022] In one embodiment, even with the coating 18, the cover 16 is still transparent or close to transparent, which permits visual inspection of the tissue 12 held in the holder 14. In such an embodiment, the coating may be very thin, which in turn means that not a lot of material is transferred and it may be difficult to see the marking with the naked eye. In such a case, it may be advantageous to use fluorescent materials, quantum dots and nanoparticles and the like, which emit strong optical responses when excited with a UV light source or a laser of a particular wavelength, therefore providing good visual or machine detectability despite the small quantity of material printed onto the tissue.

[0023] The marking process and device of the invention may be used to mark suspicious spots (e.g., pixels) on the tissue sample, wherein the marking is preserved throughout the tissue processing (e.g., freezing or stabilizing) and remains detectable (e.g., human visible or machine detectable) to the pathologist even after processing.

[0024] The laser device and/or the tissue holder may be moved to align the laser pulse with the area to be marked, such as by means of an actuator, step motor, x-y-z moving table and the like.