Expect Fed Chairman Ben Bernanke to use a speech at an annual central bank conference in Jackson Hole, Wyoming, next Friday to acknowledge his disappointment over the pace of growth, even downgrade his outlook, and explain which medicines left in the Fed's cabinet are best suited to fortify the economy.

He looks unlikely to reach for shock treatment, but the Fed could be primed to gradually boost the dosage for the ailing economy over the coming months.

One initial step might be simply to use verbal communication. It could commit to maintain its balance sheet, which has ballooned to $2.8 trillion from a pre-crisis level of around $900 billion, at this high level for an extended period of time - even adding a timeframe just as it has for the fed funds rate.

Another measure would be to put downward pressure on medium to long-term interest rates, where mortgages are fixed and corporations borrow, by taking steps to weight the mix of assets in the Fed's balance sheet toward longer-maturity instruments. This can be done either by replacing its maturing securities with longer-term ones, or by actively exchanging shorter maturities with longer ones.

A bolder step would be to buy more bonds, though conditions do not seem to merit that at this juncture. While Fed officials argue bond buying has held longer term rates lower than they would otherwise have been and moved investors to seek riskier assets than safe-haven Treasury securities, the strategy has drawn sharp criticism domestically and internationally.

As a way to tamp down worries that bond buying would spur inflation, the Fed could consider sterilizing new bond buying by simultaneously draining bank reserves. Doing so would remove risk and duration from credit markets, push down interest rates at the longer end of the yield curve, while keeping abundant reserves in check.

With interest rate tools well exploited, Bernanke is most likely to focus on the Fed's balance sheet and opt for tinkering with the size and composition of its portfolio to get the world's largest economy out of its funk.

Interest rates are already near zero, and the central bank's policy-setting Federal Open Market Committee just two weeks ago signaled it is willing to hold borrowing costs at rock bottom levels for two years if necessary. There is little more that can be achieved using the rates tool.

Many of the balance sheet steps are well known, and each carries its own risks and rewards, which Fed staff would research carefully. But chances for a major new bond buying operation announced at Jackson Hole would appear limited currently.

In shaping its thinking, the Fed is likely guided by a sense that the current situation, though rather uncertain, merits a cautious approach and does not arise to the crisis proportions seen in 2008 through 2010 that justified bold and aggressive moves.

The last of these - the $600 billion bond purchase program dubbed QE2 because it was the second installment of quantitative easing - was the Fed's response to historically low inflation that risked tipping the U.S. economy into a vicious cycle of falling prices and falling consumption and investment.

Shayne Heffernan

Shayne Heffernan oversees the management of funds for institutions and high net worth individuals.

Shayne Heffernan holds a Ph.D. in Economics and brings with him over 25 years of trading experience in Asia and hands on experience in Venture Capital, he has been involved in several start ups that have seen market capitalization over $500m and 1 that reach a peak market cap of $15b. He has managed and overseen start ups in Mining, Shipping, Technology and Financial Services.