How to suppress caption numbering in a figwindow

\documentclass[a4paper]{article}
\usepackage{picinpar}
\usepackage{graphicx}
\begin{document}

\begin{figwindow}[1,l,{\mbox{%

In this lab, you will record the standard limb leads in sequence,according to the diagram below:
The goal for the Frank electrode system is to capture the three-dimensional extent of the heart dipole.  For this, it is necessary to measure potential differences not just in the frontal plane, as in the limb leads, but along the antero-posterior (front-to-back) axis of the body.  The diagram below illustrates the original Frank lead system \cite{RSM:Fra56} and we will use a simplified version of this.
\end{figwindow}

\end{document}

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Welcome to TeX.sx! A tip: If you indent lines by 4 spaces, they'll be marked as a code sample. You can also highlight the code and click the "code" button (with "{}" on it). – henrique Sep 28 '12 at 3:07

You can define your own figwindownonum environment that doesn't set the caption using the figure type. Instead, it just prints whatever you pass it:

\documentclass[a4paper]{article}
\usepackage{picinpar}% http://ctan.org/pkg/picinpar
\usepackage{graphicx}% http://ctan.org/pkg/graphicx
\makeatletter
\long\def\figwindownonum[#1,#2,#3,#4] {% \begin{figwindownonum}
\begin{window}[#1,#2,{#3},{\centering#4\par}] }
\def\endfigwindownonum{\end{window}}% \end{figwindownonum}
\makeatother
\begin{document}

\begin{figwindownonum}[1,l,{\mbox{%
\includegraphics[width=80pt]{tiger}}},{\TeX{} Tiger}]
In this lab, you will record the standard limb leads in sequence,according to the diagram below:
The goal for the Frank electrode system is to capture the three-dimensional extent of the heart dipole.  For this, it is necessary to measure potential differences not just in the frontal plane, as in the limb leads, but along the antero-posterior (front-to-back) axis of the body.  The diagram below illustrates the original Frank lead system and we will use a simplified version of this.
In this lab, you will record the standard limb leads in sequence,according to the diagram below:
The goal for the Frank electrode system is to capture the three-dimensional extent of the heart dipole.  For this, it is necessary to measure potential differences not just in the frontal plane, as in the limb leads, but along the antero-posterior (front-to-back) axis of the body.  The diagram below illustrates the original Frank lead system and we will use a simplified version of this.
\end{figwindownonum}

\end{document}


You could also consider using the wrapfig package. Here's a small example that somewhat duplicates your usage:

\documentclass[a4paper]{article}
\usepackage{wrapfig}% http://ctan.org/pkg/wrapfig
\usepackage{graphicx}% http://ctan.org/pkg/wrapfig
\begin{document}

\begin{wrapfigure}{l}{85pt}
\centering
\includegraphics[width=80pt]{tiger} \par
\TeX{} Tiger
\end{wrapfigure}
In this lab, you will record the standard limb leads in sequence,according to the diagram below:
The goal for the Frank electrode system is to capture the three-dimensional extent of the heart dipole.  For this, it is necessary to measure potential differences not just in the frontal plane, as in the limb leads, but along the antero-posterior (front-to-back) axis of the body.  The diagram below illustrates the original Frank lead system and we will use a simplified version of this.
In this lab, you will record the standard limb leads in sequence,according to the diagram below:
The goal for the Frank electrode system is to capture the three-dimensional extent of the heart dipole.  For this, it is necessary to measure potential differences not just in the frontal plane, as in the limb leads, but along the antero-posterior (front-to-back) axis of the body.  The diagram below illustrates the original Frank lead system and we will use a simplified version of this.

\end{document}

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You can mention (as an argument in favor of wrapfig or any other replacement) the note by Piet van Oostrum in the CTAN edition entry for picinpar – Gonzalo Medina Sep 28 '12 at 3:10