A number of different types of bone cement injection procedures are routinely practiced, among which is vertebroplasty.
Unfortunately, the pressure required to inject cement can easily reach values beyond human physical limit. A number of pressure-controlled devices are available to increasing the pressure applied to the cement for delivery, however such devices may increase the risk of cement leakage because of a lack of control on the cement flow rate. It is also known to lower the cement viscosity to ease the injection, however such an approach may also generally increase the risk of cement leakage.
While most cement leaks are inconsequential, every leak nevertheless exposes patients to serious risks, such as spinal cord and nerve root compression, pulmonary embolism, and possibly even death.
Further, the viscosity of the bone cement changes as the cement polymerizes, while also varying substantially due to various factors such as environmental conditions (e.g. temperature, humidity), the mixing technique used, as well as the batch and type of cement used. Physicians often use suggestive methods such as visual and/or tactile inspection to evaluate whether the viscosity of cement is adequate for injection, such methods being generally imprecise and not easily reproducible.
Accordingly, improvements are desirable.
USPTO Backgrounds
USPTO Backgrounds