<s>
A	O
volumetric	B-General_Concept
haptic	I-General_Concept
display	I-General_Concept
(	O
VHD	O
)	O
is	O
similar	O
to	O
a	O
(	O
visual	O
)	O
volumetric	B-Algorithm
display	I-Algorithm
,	O
but	O
informs	O
touch	O
instead	O
of	O
vision	O
.	O
</s>
<s>
The	O
University	O
of	O
Bristol	O
has	O
developed	O
a	O
method	O
for	O
haptic	B-Device
feedback	O
that	O
could	O
be	O
integrated	O
into	O
a	O
volumetric	B-Algorithm
display	I-Algorithm
.	O
</s>
<s>
The	O
system	O
uses	O
focused	O
ultrasound	O
to	O
create	O
a	O
haptic	B-Device
object	O
in	O
mid	O
air	O
.	O
</s>
