A blood pressure monitor is an important piece of examination equipment.
Literal
Blood-pressure-meter [subject-が] important examination instrument [copula-です].
A simple declarative medical sentence. 血圧計 (けつあつけい, 'blood pressure gauge/monitor') is a three-kanji compound: 血 (blood) + 圧 (pressure) + 計 (meter). 検査器械 (けんさきかい, 'examination instrument') uses 器械 (equipment/apparatus), a slightly more formal variant of 器械. 大切な ('important') modifies the noun. The sentence reads like a medical textbook or training manual statement.