First-quarter sales for Neurometrix Inc. dropped 22 percent, as the company felt the pinch of a national slowdown in the capital equipment market.

The Waltham-based neurological testing equipment manufacturer posted sales of $6.8 million for the quarter, compared with $8.7 million for the same period last year. But 90 percent of those sales were derived from consumables, with medical equipment making up less than 10 percent.

Medical equipment revenues include sales of the company’s Advance device and its NC-stat module. Consumables revenues include sales of nerve specific electrodes, EMG needles and other accessories.

The sluggish sales didn’t affect the bottom line, as Neurometrix managed to narrow its net loss. The company posted losses of $1.2 million during the three-month period ended March 31, compared to a nearly $11 million loss for the same period last year.

Neurometrix trimmed about $10 million in expenses during the quarter by slashing its sales force by 40 percent during the second quarter last year. In March the company let go of Monty Hukill, the VP of diagnostics device sales, as it looked to restructure its sales force into three divisions.

Cash and cash equivalents were down sharply, from $12.3 million for the same period in 2008 to just $5.9 million this quarter. The company paid $3.7 million to the U.S. Department of Justice to settle charges in a Medicare fraud and federal kickbacks case during the quarter.

Under a deferred prosecution deal with former U.S. Attorney Michael Sullivan’s office in Boston and the federal Health and the Inspector General’s office of the federal Health & Human Services Dept., Neurometrix agreed in February to a $1.2 million fine to settle accusations of illegal kickbacks to physicians and $2.5 million to settle civil charges in that case and another alleged Medicare billing scam.