Masimo (NSDQ:MASI) shares are up following the Irvine, Calif.-based medical device company’s solid 1st-quarter results, gaining some 7% since last week’s earnings announcement.

Masimo, which makes patient monitoring equipment, posted profits of $16.4 million, or 28¢ per share, on sales of $135.9 million during the 3 months ended March 30, for bottom-line growth of 4.1% and a top-line gain of 14.0%.

"Masimo is off to a solid start in 2013, with product revenue up 15%, fueled by a 14% rise in our core SET Pulse Oximetry business and a 24% rise in sales of rainbow SET Pulse CO-Oximetry and other rainbow related products," founder, chairman & CEO Joe Kiani said in prepared remarks. "The 19% increase in driver shipments in the quarter further underscores the growing demand for our superior technology in hospitals and alternate care settings worldwide. In addition, we took advantage of strong cash flows in the quarter to repurchase 778,000 shares of Masimo common stock, demonstrating our confidence in the company’s strategy, business model and future growth prospects."

During a conference call with investors last week, Masimo CFO Mark de Raad affirmed Masimo’s sales guidance for the rest of the year at $548 million.

MASI shares were trading at $21.30 as of about 12:30 p.m. today, up 7.3% over their May 1 close.