To pass the door of 7th stage of chapter 3 silent hospital, look for the blood type and use the code to get some numbers !

Doors and Rooms Level 3-7 Walkthrough
first take a look the code that requires to open the door :
it’s blood type : RH-O A B RH-A O AB
use the microscope and chart to find these blood types code number :)
see the cheat answer below !
doors-and-rooms-walkthrough

doors & rooms stage 3-7 solution :
first, find all these items :
take 2 bottles of anti-D and anti-A on the shelf
2 parts of microscope inside 2 drawers and a bottle of anti-B on the right drawer
open the grey box above the right drawer for blood sample
get a note from shelf right to the door

now click the blood type on the table
use anti-A anti-B and anti-D bottles on these blood samples
you will see some blood changed into yellow
look at the chart on the wall so now you will have :
Sila (AB), Uj (RH-O), Ruly (A), Aska (RH-A) Miro (B), Max (O)

observe the paper inside your inventory
there are 3 symbols on the paper :
(black circle, white circle, star)
using the correct math you must find out the value of each symbol
12 = 2x● + 2x○ + 2x☆
14 = 2x● + 2x○ + 4x☆
10 = 1x● + 3x○ + 1x☆

so you should have :
● = 2 ○ = 3 ☆ = 1

put 2 part of items on microscope from inventory
and put the blood sample here, now start the math :
sila(6), uj(6), ruly(9), aska(9), miro(7), max(5)

so click the panel near door and blood type RH-O, A, B, RH-A, O, AB to enter : 697 956
see you on next update :D