 	o2		int,
 	timestamp	time,
 	ses_no	int,
+	devicetype	char(10),
 	primary key (ahcn)
 )
 create table bpressure(

	timestamp	time,
	datestamp	date,
	primary key (timestamp)
)
create table account(
	username	varchar(10),
	password	varchar(20),
	primary key (password)
)	
	map		int,
	timestamp	time,
	ses_no	int,
	devicetype	char(10),
	primary key (ahcn)
)
create table oximiter(
