A time resolved intense pulsed light spectral analysis system

Abstract

Intense pulsed light systems are currently in widespread use in clinical applications. Verification of spectral content and associated pulse waveforms is, however, not featured in product support and calibration. A measurement system was developed to determine the spectral output of such sources within a series of discrete wavelength intervals. Such a system utilised a series of 11 broadband optical filters with centre wavelengths within the range 450-950 nm in circuit with silicon photodiodes as optical detectors. Signals were captured using a low cost 8-channel 16-bit universal serial bus data capture module interfaced to a laptop computer. This allowed the pulse profile of selected filter components to be separately captured and analysed. Calibration of individual filter channels was undertaken using a Bentham dmc150 spectroradiometer and reference tungsten light source. Initial measurements undertaken of the intense pulsed light output of a Lumenis One system using the system are described.

Relevance of the structure of time‐resolved spectral output to light‐tissue interaction using intense pulsed light (IPL)

“…Whilst the role of measurement of pulse duration and pulse profile for lasers and intense pulsed light sources has been recognised recently [7,8], only a few studies to date have attempted to document methods for measuring IPL pulse durations or examine in detail the time-resolved spectral output of IPLs that is across each millisecond of the pulse duration [8][9][10]. Time-resolved spectroscopy graphically modelled using MathCAD TM software is intended to demonstrate simply the light energy distribution Fig.…”

Confirmation of spectral jitter: a measured shift in the spectral distribution of intense pulsed light systems using a time-resolved spectrometer during exposure and increased fluence

“…There is only limited published literature on the measurement of IPL devices [16][17][18][19][20][21][22]. Town et al [23] identified five key IPL measurement parameters: pulse duration, radiant exposure (fluence), spatial profile, spectral output and time-resolved spectral output.…”

“…Time-resolved spectral measurement is significant in optimizing treatment parameters and assessing clinical and ocular hazards [20][21][22]. Different absorption characteristics of chromophore targets in skin (figure 1) require that sufficient energy be delivered in the wavelength range that is most likely to be biologically effective, whilst minimizing adverse reactions by filtering potentially damaging wavelengths being delivered to the tissue matrix.…”